Page 1
JEE Main Previous Year Questions
(2025): Linear Inequalities
Q1: If the equation ?? ( ?? - ?? ) ?? ?? + ?? ( ?? - ?? ) ?? + ?? ( ?? - ?? ) = ?? has equal roots, where
?? + ?? = ???? and ?? =
????
?? , then ?? ?? + ?? ?? is equal to _ _ _ _
JEE Main 2025 (Online) 23rd January Morning Shift
Ans: 117
Solution:
To solve the given problem, we start with the quadratic equation:
?? ( ?? - ?? ) ?? 2
+ ?? ( ?? - ?? ) ?? + ?? ( ?? - ?? ) = 0
Given that the roots are equal (let's assume both roots are 1 ), we know the sum of the roots,
?? + ?? , is twice the value of one root, which leads us to:
?? + ?? = 2
Using the formula for the sum of roots for a quadratic equation, ?? + ?? = -
?? ( ?? - ?? )
?? ( ?? - ?? )
, we set this
equal to 2 :
-
?? ( ?? - ?? )
?? ( ?? - ?? )
= 2
Solving for this:
- ???? + ???? = 2 ???? - 2 ???? 2 ???? = ???? + ???? 2 ???? = ?? ( ?? + ?? )
Given that ?? + ?? = 15 and ?? =
36
5
, substitute these into the equation:
2 ???? = 15 ?? 2 ???? = 15 ×
36
5
= 108 ???? = 54
Now, using the equation ?? + ?? = 15 and ???? = 54, find ?? 2
+ ?? 2
:
?? 2
+ ?? 2
= ( ?? + ?? )
2
- 2 ???? = 15
2
- 2 × 54 ?? 2
+ ?? 2
= 225 - 108 = 117
Therefore, ?? 2
+ ?? 2
is equal to 117 .
Q2: If the set of all ?? ? ?? - { ?? }, for which the roots of the equation ( ?? - ?? ) ?? ?? +
?? ( ?? - ?? ) ?? + ?? = ?? are positive is ( - 8 , - ?? ] ? [ ?? , ?? ) , then ?? ?? + ?? + ?? is equal to
JEE Main 2025 (Online) 2nd April Evening Shift
Ans: 7
Solution:
?? ( ?? ) = ( 1 - ?? ) ?? 2
+ 2 ( ?? - 3 ) ?? + 9 , ?? ( 0 ) = 9 > 0
?? = 0 ? 4 ( ?? - 3 )
2
= 4 ( 1 - ?? ) · 9
? ?? ? ( - 8 , - 3 ] ? [ 0 , 8 ) ( ?? )
Page 2
JEE Main Previous Year Questions
(2025): Linear Inequalities
Q1: If the equation ?? ( ?? - ?? ) ?? ?? + ?? ( ?? - ?? ) ?? + ?? ( ?? - ?? ) = ?? has equal roots, where
?? + ?? = ???? and ?? =
????
?? , then ?? ?? + ?? ?? is equal to _ _ _ _
JEE Main 2025 (Online) 23rd January Morning Shift
Ans: 117
Solution:
To solve the given problem, we start with the quadratic equation:
?? ( ?? - ?? ) ?? 2
+ ?? ( ?? - ?? ) ?? + ?? ( ?? - ?? ) = 0
Given that the roots are equal (let's assume both roots are 1 ), we know the sum of the roots,
?? + ?? , is twice the value of one root, which leads us to:
?? + ?? = 2
Using the formula for the sum of roots for a quadratic equation, ?? + ?? = -
?? ( ?? - ?? )
?? ( ?? - ?? )
, we set this
equal to 2 :
-
?? ( ?? - ?? )
?? ( ?? - ?? )
= 2
Solving for this:
- ???? + ???? = 2 ???? - 2 ???? 2 ???? = ???? + ???? 2 ???? = ?? ( ?? + ?? )
Given that ?? + ?? = 15 and ?? =
36
5
, substitute these into the equation:
2 ???? = 15 ?? 2 ???? = 15 ×
36
5
= 108 ???? = 54
Now, using the equation ?? + ?? = 15 and ???? = 54, find ?? 2
+ ?? 2
:
?? 2
+ ?? 2
= ( ?? + ?? )
2
- 2 ???? = 15
2
- 2 × 54 ?? 2
+ ?? 2
= 225 - 108 = 117
Therefore, ?? 2
+ ?? 2
is equal to 117 .
Q2: If the set of all ?? ? ?? - { ?? }, for which the roots of the equation ( ?? - ?? ) ?? ?? +
?? ( ?? - ?? ) ?? + ?? = ?? are positive is ( - 8 , - ?? ] ? [ ?? , ?? ) , then ?? ?? + ?? + ?? is equal to
JEE Main 2025 (Online) 2nd April Evening Shift
Ans: 7
Solution:
?? ( ?? ) = ( 1 - ?? ) ?? 2
+ 2 ( ?? - 3 ) ?? + 9 , ?? ( 0 ) = 9 > 0
?? = 0 ? 4 ( ?? - 3 )
2
= 4 ( 1 - ?? ) · 9
? ?? ? ( - 8 , - 3 ] ? [ 0 , 8 ) ( ?? )
?? 1
+ ?? 2
=
- 2 ( ?? - 3 )
1 - ?? , ?? 1
?? 2
=
9
1 - ??
?? 1
+ ?? 2
> 0 ?
?? - 3
?? - 1
> 0 ? ?? ? ( - 8 , 1 ) ? ( 3 , 8 ) … ( ???? )
?? 1
?? 2
> 0 ? 1 - ?? > 0 ? ?? ? ( - 8 , 1 ) ( ?????? )
? Interaction of (i), (ii) and (iii)
?? ? ( - 8 , - 3 ] ? [ 0 , 1 )
? ?? = 3 , ?? = 0 , ?? = 1 ? 2 ?? + ?? + ?? = 7
Q3: Let ?? ?? and ?? ?? be the distinct roots of ?? ?? ?? + ( ?? ?? ?? ? ?? ) ?? - ?? = ?? , ?? ? ( ?? , ?? ?? ) . If ??
and ?? are the minimum and the maximum values of ?? ?? ?? + ?? ?? ?? , then ???? ( ?? + ?? )
equals :
JEE Main 2025 (Online) 22nd January Evening Shift
Options:
A. 27
B. 17
C. 25
D. 24
Ans: C
Solution:
To find the sum of the fourth powers of the roots ?? ?? and ?? ?? of the quadratic equation 2 ?? 2
+
( c os ? ?? ) ?? - 1 = 0, we start analyzing the expression ?? ?? 4
+ ?? ?? 4
.
Page 3
JEE Main Previous Year Questions
(2025): Linear Inequalities
Q1: If the equation ?? ( ?? - ?? ) ?? ?? + ?? ( ?? - ?? ) ?? + ?? ( ?? - ?? ) = ?? has equal roots, where
?? + ?? = ???? and ?? =
????
?? , then ?? ?? + ?? ?? is equal to _ _ _ _
JEE Main 2025 (Online) 23rd January Morning Shift
Ans: 117
Solution:
To solve the given problem, we start with the quadratic equation:
?? ( ?? - ?? ) ?? 2
+ ?? ( ?? - ?? ) ?? + ?? ( ?? - ?? ) = 0
Given that the roots are equal (let's assume both roots are 1 ), we know the sum of the roots,
?? + ?? , is twice the value of one root, which leads us to:
?? + ?? = 2
Using the formula for the sum of roots for a quadratic equation, ?? + ?? = -
?? ( ?? - ?? )
?? ( ?? - ?? )
, we set this
equal to 2 :
-
?? ( ?? - ?? )
?? ( ?? - ?? )
= 2
Solving for this:
- ???? + ???? = 2 ???? - 2 ???? 2 ???? = ???? + ???? 2 ???? = ?? ( ?? + ?? )
Given that ?? + ?? = 15 and ?? =
36
5
, substitute these into the equation:
2 ???? = 15 ?? 2 ???? = 15 ×
36
5
= 108 ???? = 54
Now, using the equation ?? + ?? = 15 and ???? = 54, find ?? 2
+ ?? 2
:
?? 2
+ ?? 2
= ( ?? + ?? )
2
- 2 ???? = 15
2
- 2 × 54 ?? 2
+ ?? 2
= 225 - 108 = 117
Therefore, ?? 2
+ ?? 2
is equal to 117 .
Q2: If the set of all ?? ? ?? - { ?? }, for which the roots of the equation ( ?? - ?? ) ?? ?? +
?? ( ?? - ?? ) ?? + ?? = ?? are positive is ( - 8 , - ?? ] ? [ ?? , ?? ) , then ?? ?? + ?? + ?? is equal to
JEE Main 2025 (Online) 2nd April Evening Shift
Ans: 7
Solution:
?? ( ?? ) = ( 1 - ?? ) ?? 2
+ 2 ( ?? - 3 ) ?? + 9 , ?? ( 0 ) = 9 > 0
?? = 0 ? 4 ( ?? - 3 )
2
= 4 ( 1 - ?? ) · 9
? ?? ? ( - 8 , - 3 ] ? [ 0 , 8 ) ( ?? )
?? 1
+ ?? 2
=
- 2 ( ?? - 3 )
1 - ?? , ?? 1
?? 2
=
9
1 - ??
?? 1
+ ?? 2
> 0 ?
?? - 3
?? - 1
> 0 ? ?? ? ( - 8 , 1 ) ? ( 3 , 8 ) … ( ???? )
?? 1
?? 2
> 0 ? 1 - ?? > 0 ? ?? ? ( - 8 , 1 ) ( ?????? )
? Interaction of (i), (ii) and (iii)
?? ? ( - 8 , - 3 ] ? [ 0 , 1 )
? ?? = 3 , ?? = 0 , ?? = 1 ? 2 ?? + ?? + ?? = 7
Q3: Let ?? ?? and ?? ?? be the distinct roots of ?? ?? ?? + ( ?? ?? ?? ? ?? ) ?? - ?? = ?? , ?? ? ( ?? , ?? ?? ) . If ??
and ?? are the minimum and the maximum values of ?? ?? ?? + ?? ?? ?? , then ???? ( ?? + ?? )
equals :
JEE Main 2025 (Online) 22nd January Evening Shift
Options:
A. 27
B. 17
C. 25
D. 24
Ans: C
Solution:
To find the sum of the fourth powers of the roots ?? ?? and ?? ?? of the quadratic equation 2 ?? 2
+
( c os ? ?? ) ?? - 1 = 0, we start analyzing the expression ?? ?? 4
+ ?? ?? 4
.
The equation can be rewritten with its roots using:
?? + ?? = -
c os ? ?? 2
, ???? = -
1
2
We need to calculate ?? 2
+ ?? 2
and ?? 2
?? 2
:
?? 2
+ ?? 2
= ( ?? + ?? )
2
- 2 ???? = ( -
c os ? ?? 2
)
2
- 2 ( -
1
2
) =
c os
2
? ?? 4
+ 1
?? 2
?? 2
= ( ???? )
2
= ( -
1
2
)
2
=
1
4
Substitute these into:
?? 4
+ ?? 4
= ( ?? 2
+ ?? 2
)
2
- 2 ?? 2
?? 2
= (
c o s
2
? ?? 4
+ 1 )
2
-
1
2
Maximize and minimize (
c os
2
? ?? 4
+ 1 )
2
:
Zero of c os ? ?? leads to:
(
0
2
4
+ 1 )
2
= 1
Max value c os
2
? ?? = 1 :
(
1
4
+ 1 )
2
= (
5
4
)
2
=
25
16
Substitute back:
Max:
25
16
-
1
2
=
25
16
-
8
16
=
17
16
Min: 1 -
1
2
=
1
2
Finally, compute 16 ( ?? + ?? ) :
16 (
17
16
+
1
2
) = 16 (
17
16
+
8
16
) = 16 ×
25
16
= 25
Q4: The product of all the rational roots of the equation ( ?? ?? - ?? ?? + ???? )
?? - ( ?? -
?? ) ( ?? - ?? ) = ?? , is equal to
JEE Main 2025 (Online) 24th January Morning Shift
Options:
A. 7
B. 21
C. 28
D. 14
Ans: D
Solution:
To solve the given equation, start by rewriting the expression:
( ?? 2
- 9 ?? + 11 )
2
- ( ?? - 4 ) ( ?? - 5 ) = 3
First, simplify the second part of the expression:
( ?? - 4 ) ( ?? - 5 ) = ?? 2
- 9 ?? + 20
Page 4
JEE Main Previous Year Questions
(2025): Linear Inequalities
Q1: If the equation ?? ( ?? - ?? ) ?? ?? + ?? ( ?? - ?? ) ?? + ?? ( ?? - ?? ) = ?? has equal roots, where
?? + ?? = ???? and ?? =
????
?? , then ?? ?? + ?? ?? is equal to _ _ _ _
JEE Main 2025 (Online) 23rd January Morning Shift
Ans: 117
Solution:
To solve the given problem, we start with the quadratic equation:
?? ( ?? - ?? ) ?? 2
+ ?? ( ?? - ?? ) ?? + ?? ( ?? - ?? ) = 0
Given that the roots are equal (let's assume both roots are 1 ), we know the sum of the roots,
?? + ?? , is twice the value of one root, which leads us to:
?? + ?? = 2
Using the formula for the sum of roots for a quadratic equation, ?? + ?? = -
?? ( ?? - ?? )
?? ( ?? - ?? )
, we set this
equal to 2 :
-
?? ( ?? - ?? )
?? ( ?? - ?? )
= 2
Solving for this:
- ???? + ???? = 2 ???? - 2 ???? 2 ???? = ???? + ???? 2 ???? = ?? ( ?? + ?? )
Given that ?? + ?? = 15 and ?? =
36
5
, substitute these into the equation:
2 ???? = 15 ?? 2 ???? = 15 ×
36
5
= 108 ???? = 54
Now, using the equation ?? + ?? = 15 and ???? = 54, find ?? 2
+ ?? 2
:
?? 2
+ ?? 2
= ( ?? + ?? )
2
- 2 ???? = 15
2
- 2 × 54 ?? 2
+ ?? 2
= 225 - 108 = 117
Therefore, ?? 2
+ ?? 2
is equal to 117 .
Q2: If the set of all ?? ? ?? - { ?? }, for which the roots of the equation ( ?? - ?? ) ?? ?? +
?? ( ?? - ?? ) ?? + ?? = ?? are positive is ( - 8 , - ?? ] ? [ ?? , ?? ) , then ?? ?? + ?? + ?? is equal to
JEE Main 2025 (Online) 2nd April Evening Shift
Ans: 7
Solution:
?? ( ?? ) = ( 1 - ?? ) ?? 2
+ 2 ( ?? - 3 ) ?? + 9 , ?? ( 0 ) = 9 > 0
?? = 0 ? 4 ( ?? - 3 )
2
= 4 ( 1 - ?? ) · 9
? ?? ? ( - 8 , - 3 ] ? [ 0 , 8 ) ( ?? )
?? 1
+ ?? 2
=
- 2 ( ?? - 3 )
1 - ?? , ?? 1
?? 2
=
9
1 - ??
?? 1
+ ?? 2
> 0 ?
?? - 3
?? - 1
> 0 ? ?? ? ( - 8 , 1 ) ? ( 3 , 8 ) … ( ???? )
?? 1
?? 2
> 0 ? 1 - ?? > 0 ? ?? ? ( - 8 , 1 ) ( ?????? )
? Interaction of (i), (ii) and (iii)
?? ? ( - 8 , - 3 ] ? [ 0 , 1 )
? ?? = 3 , ?? = 0 , ?? = 1 ? 2 ?? + ?? + ?? = 7
Q3: Let ?? ?? and ?? ?? be the distinct roots of ?? ?? ?? + ( ?? ?? ?? ? ?? ) ?? - ?? = ?? , ?? ? ( ?? , ?? ?? ) . If ??
and ?? are the minimum and the maximum values of ?? ?? ?? + ?? ?? ?? , then ???? ( ?? + ?? )
equals :
JEE Main 2025 (Online) 22nd January Evening Shift
Options:
A. 27
B. 17
C. 25
D. 24
Ans: C
Solution:
To find the sum of the fourth powers of the roots ?? ?? and ?? ?? of the quadratic equation 2 ?? 2
+
( c os ? ?? ) ?? - 1 = 0, we start analyzing the expression ?? ?? 4
+ ?? ?? 4
.
The equation can be rewritten with its roots using:
?? + ?? = -
c os ? ?? 2
, ???? = -
1
2
We need to calculate ?? 2
+ ?? 2
and ?? 2
?? 2
:
?? 2
+ ?? 2
= ( ?? + ?? )
2
- 2 ???? = ( -
c os ? ?? 2
)
2
- 2 ( -
1
2
) =
c os
2
? ?? 4
+ 1
?? 2
?? 2
= ( ???? )
2
= ( -
1
2
)
2
=
1
4
Substitute these into:
?? 4
+ ?? 4
= ( ?? 2
+ ?? 2
)
2
- 2 ?? 2
?? 2
= (
c o s
2
? ?? 4
+ 1 )
2
-
1
2
Maximize and minimize (
c os
2
? ?? 4
+ 1 )
2
:
Zero of c os ? ?? leads to:
(
0
2
4
+ 1 )
2
= 1
Max value c os
2
? ?? = 1 :
(
1
4
+ 1 )
2
= (
5
4
)
2
=
25
16
Substitute back:
Max:
25
16
-
1
2
=
25
16
-
8
16
=
17
16
Min: 1 -
1
2
=
1
2
Finally, compute 16 ( ?? + ?? ) :
16 (
17
16
+
1
2
) = 16 (
17
16
+
8
16
) = 16 ×
25
16
= 25
Q4: The product of all the rational roots of the equation ( ?? ?? - ?? ?? + ???? )
?? - ( ?? -
?? ) ( ?? - ?? ) = ?? , is equal to
JEE Main 2025 (Online) 24th January Morning Shift
Options:
A. 7
B. 21
C. 28
D. 14
Ans: D
Solution:
To solve the given equation, start by rewriting the expression:
( ?? 2
- 9 ?? + 11 )
2
- ( ?? - 4 ) ( ?? - 5 ) = 3
First, simplify the second part of the expression:
( ?? - 4 ) ( ?? - 5 ) = ?? 2
- 9 ?? + 20
Now the equation becomes:
( ?? 2
- 9 ?? + 11 )
2
- ( ?? 2
- 9 ?? + 20 ) = 3
Introduce a substitution for simplification:
Let ?? = ?? 2
- 9 ??
Thus, the equation transforms to:
?? 2
+ 22 ?? + 121 - ?? - 20 - 3 = 0
Simplify further:
?? 2
+ 21 ?? + 98 = 0
Factor the quadratic:
( ?? + 14 ) ( ?? + 7 ) = 0
This gives:
?? = - 7 ? or ? ?? = - 14
Address each case where ?? = ?? 2
- 9 ?? :
?? 2
- 9 ?? = - 7
?? 2
- 9 ?? + 7 = 0
Solving this quadratic equation, we find the roots:
?? =
9 ± v 81 - 4 × 7
2
=
9 ± v 53
2
?? 2
- 9 ?? = - 14
?? 2
- 9 ?? + 14 = 0
Solving this quadratic equation:
?? =
9 ± v 81 - 4 × 14
2
=
9 ± v 25
2
?? =
9 ± 5
2
= 7 ? or ? ?? = 2
The rational roots from the second equation are 7 and 2 . Thus, the product of all the rational
roots is:
7 × 2 = 14
Q5: The number of real solution(s) of the equation
?? ?? + ?? ?? + ?? = ?? ???? { | ?? - ?? | , | ?? + ?? | } is :
JEE Main 2025 (Online) 24th January Evening Shift
Options:
A. 2
B. 3
C. 1
D. 0
Ans: A
Solution:
Page 5
JEE Main Previous Year Questions
(2025): Linear Inequalities
Q1: If the equation ?? ( ?? - ?? ) ?? ?? + ?? ( ?? - ?? ) ?? + ?? ( ?? - ?? ) = ?? has equal roots, where
?? + ?? = ???? and ?? =
????
?? , then ?? ?? + ?? ?? is equal to _ _ _ _
JEE Main 2025 (Online) 23rd January Morning Shift
Ans: 117
Solution:
To solve the given problem, we start with the quadratic equation:
?? ( ?? - ?? ) ?? 2
+ ?? ( ?? - ?? ) ?? + ?? ( ?? - ?? ) = 0
Given that the roots are equal (let's assume both roots are 1 ), we know the sum of the roots,
?? + ?? , is twice the value of one root, which leads us to:
?? + ?? = 2
Using the formula for the sum of roots for a quadratic equation, ?? + ?? = -
?? ( ?? - ?? )
?? ( ?? - ?? )
, we set this
equal to 2 :
-
?? ( ?? - ?? )
?? ( ?? - ?? )
= 2
Solving for this:
- ???? + ???? = 2 ???? - 2 ???? 2 ???? = ???? + ???? 2 ???? = ?? ( ?? + ?? )
Given that ?? + ?? = 15 and ?? =
36
5
, substitute these into the equation:
2 ???? = 15 ?? 2 ???? = 15 ×
36
5
= 108 ???? = 54
Now, using the equation ?? + ?? = 15 and ???? = 54, find ?? 2
+ ?? 2
:
?? 2
+ ?? 2
= ( ?? + ?? )
2
- 2 ???? = 15
2
- 2 × 54 ?? 2
+ ?? 2
= 225 - 108 = 117
Therefore, ?? 2
+ ?? 2
is equal to 117 .
Q2: If the set of all ?? ? ?? - { ?? }, for which the roots of the equation ( ?? - ?? ) ?? ?? +
?? ( ?? - ?? ) ?? + ?? = ?? are positive is ( - 8 , - ?? ] ? [ ?? , ?? ) , then ?? ?? + ?? + ?? is equal to
JEE Main 2025 (Online) 2nd April Evening Shift
Ans: 7
Solution:
?? ( ?? ) = ( 1 - ?? ) ?? 2
+ 2 ( ?? - 3 ) ?? + 9 , ?? ( 0 ) = 9 > 0
?? = 0 ? 4 ( ?? - 3 )
2
= 4 ( 1 - ?? ) · 9
? ?? ? ( - 8 , - 3 ] ? [ 0 , 8 ) ( ?? )
?? 1
+ ?? 2
=
- 2 ( ?? - 3 )
1 - ?? , ?? 1
?? 2
=
9
1 - ??
?? 1
+ ?? 2
> 0 ?
?? - 3
?? - 1
> 0 ? ?? ? ( - 8 , 1 ) ? ( 3 , 8 ) … ( ???? )
?? 1
?? 2
> 0 ? 1 - ?? > 0 ? ?? ? ( - 8 , 1 ) ( ?????? )
? Interaction of (i), (ii) and (iii)
?? ? ( - 8 , - 3 ] ? [ 0 , 1 )
? ?? = 3 , ?? = 0 , ?? = 1 ? 2 ?? + ?? + ?? = 7
Q3: Let ?? ?? and ?? ?? be the distinct roots of ?? ?? ?? + ( ?? ?? ?? ? ?? ) ?? - ?? = ?? , ?? ? ( ?? , ?? ?? ) . If ??
and ?? are the minimum and the maximum values of ?? ?? ?? + ?? ?? ?? , then ???? ( ?? + ?? )
equals :
JEE Main 2025 (Online) 22nd January Evening Shift
Options:
A. 27
B. 17
C. 25
D. 24
Ans: C
Solution:
To find the sum of the fourth powers of the roots ?? ?? and ?? ?? of the quadratic equation 2 ?? 2
+
( c os ? ?? ) ?? - 1 = 0, we start analyzing the expression ?? ?? 4
+ ?? ?? 4
.
The equation can be rewritten with its roots using:
?? + ?? = -
c os ? ?? 2
, ???? = -
1
2
We need to calculate ?? 2
+ ?? 2
and ?? 2
?? 2
:
?? 2
+ ?? 2
= ( ?? + ?? )
2
- 2 ???? = ( -
c os ? ?? 2
)
2
- 2 ( -
1
2
) =
c os
2
? ?? 4
+ 1
?? 2
?? 2
= ( ???? )
2
= ( -
1
2
)
2
=
1
4
Substitute these into:
?? 4
+ ?? 4
= ( ?? 2
+ ?? 2
)
2
- 2 ?? 2
?? 2
= (
c o s
2
? ?? 4
+ 1 )
2
-
1
2
Maximize and minimize (
c os
2
? ?? 4
+ 1 )
2
:
Zero of c os ? ?? leads to:
(
0
2
4
+ 1 )
2
= 1
Max value c os
2
? ?? = 1 :
(
1
4
+ 1 )
2
= (
5
4
)
2
=
25
16
Substitute back:
Max:
25
16
-
1
2
=
25
16
-
8
16
=
17
16
Min: 1 -
1
2
=
1
2
Finally, compute 16 ( ?? + ?? ) :
16 (
17
16
+
1
2
) = 16 (
17
16
+
8
16
) = 16 ×
25
16
= 25
Q4: The product of all the rational roots of the equation ( ?? ?? - ?? ?? + ???? )
?? - ( ?? -
?? ) ( ?? - ?? ) = ?? , is equal to
JEE Main 2025 (Online) 24th January Morning Shift
Options:
A. 7
B. 21
C. 28
D. 14
Ans: D
Solution:
To solve the given equation, start by rewriting the expression:
( ?? 2
- 9 ?? + 11 )
2
- ( ?? - 4 ) ( ?? - 5 ) = 3
First, simplify the second part of the expression:
( ?? - 4 ) ( ?? - 5 ) = ?? 2
- 9 ?? + 20
Now the equation becomes:
( ?? 2
- 9 ?? + 11 )
2
- ( ?? 2
- 9 ?? + 20 ) = 3
Introduce a substitution for simplification:
Let ?? = ?? 2
- 9 ??
Thus, the equation transforms to:
?? 2
+ 22 ?? + 121 - ?? - 20 - 3 = 0
Simplify further:
?? 2
+ 21 ?? + 98 = 0
Factor the quadratic:
( ?? + 14 ) ( ?? + 7 ) = 0
This gives:
?? = - 7 ? or ? ?? = - 14
Address each case where ?? = ?? 2
- 9 ?? :
?? 2
- 9 ?? = - 7
?? 2
- 9 ?? + 7 = 0
Solving this quadratic equation, we find the roots:
?? =
9 ± v 81 - 4 × 7
2
=
9 ± v 53
2
?? 2
- 9 ?? = - 14
?? 2
- 9 ?? + 14 = 0
Solving this quadratic equation:
?? =
9 ± v 81 - 4 × 14
2
=
9 ± v 25
2
?? =
9 ± 5
2
= 7 ? or ? ?? = 2
The rational roots from the second equation are 7 and 2 . Thus, the product of all the rational
roots is:
7 × 2 = 14
Q5: The number of real solution(s) of the equation
?? ?? + ?? ?? + ?? = ?? ???? { | ?? - ?? | , | ?? + ?? | } is :
JEE Main 2025 (Online) 24th January Evening Shift
Options:
A. 2
B. 3
C. 1
D. 0
Ans: A
Solution:
Only 2 solutions.
Q6: The sum, of the squares of all the roots of the equation ?? ?? + | ?? ?? - ?? | - ?? = ?? , is
JEE Main 2025 (Online) 28th January Morning Shift
Options:
A. 6 ( 2 - v 2 )
B. 3 ( 3 - v 2 )
C. 3 ( 2 - v 2 )
D. 6 ( 3 - v 2 )
Ans: A
Solution:
To find the sum of the squares of all the roots of the equation ?? 2
+ | 2 ?? - 3 | - 4 = 0 :
Case I: ?? =
3
2
For ?? =
3
2
, the expression | 2 ?? - 3 | becomes 2 ?? - 3. Thus, the equation becomes:
?? 2
+ 2 ?? - 3 - 4 = 0
Simplifying gives:
?? 2
+ 2 ?? - 7 = 0
Solving this quadratic equation, we find:
?? = 2 v 2 - 1
Case II: ?? <
3
2
For ?? <
3
2
, the expression | 2 ?? - 3 | becomes - ( 2 ?? - 3 ) = - 2 ?? + 3. The equation therefore
becomes:
?? 2
+ 3 - 2 ?? - 4 = 0
Simplifying gives:
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