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If the system of linear equations
2x + 2ay + az = 0
2x + 3by + bz = 0 and
2x + 4cy + cz = 0,
where a, b, c Є R are non-zero and distinct; has non-zero solution, then
  • a)
    1/a, 1/b, 1/c are in A.P.
  • b)
    a + b + c = 0
  • c)
    a, b, c are in A.P.
  • d)
    a, b, c are in G.P.
Correct answer is option 'A'. Can you explain this answer?
Most Upvoted Answer
If the system of linear equations2x + 2ay + az = 02x + 3by + bz = 0 an...
Given system of linear equations
2x + 2ay + az = 0
2x + 3by + bz = 0 and
2x + 4cy + cz = 0,
Now,
=> (3b − 2a)(c − a) − (4c − 2a)(b − a) = 0
=> 3bc − 2ac − 3ab + 2a2 − [4bc − 4ac − 2ab + 2a2] = 0
=> −bc + 2ac − ab = 0
=> ab + bc = 2ac
=> 1/c + 1/a = 2/b
Which shows that 1/a, 1/b, 1/c are in A.P.
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Community Answer
If the system of linear equations2x + 2ay + az = 02x + 3by + bz = 0 an...
To solve this problem, let's first rewrite the system of linear equations in matrix form:

⎡ 2 2a a ⎤ ⎡ x ⎤ ⎡ 0 ⎤
⎢ 2 3b b ⎥ ⋅ ⎢ y ⎥ = ⎢ 0 ⎥
⎣ 2 4c c ⎦ ⎣ z ⎦ ⎣ 0 ⎦

Next, let's find the determinant of the coefficient matrix:

| 2 2a a |
| 2 3b b |
| 2 4c c |

Expanding the determinant along the first row, we get:

2(3b - 4c) - 2a(2b - 2c) + a(2b - 3c)
= 6b - 8c - 4ab + 4ac + 2ab - 3ac
= -2ab + ac + 6b - 3c - 8c

Since the determinant is equal to zero for the system to have a non-zero solution, we have:

-2ab + ac + 6b - 3c - 8c = 0
-2ab + ac + 6b - 11c = 0

Now, let's simplify this equation:

a(c - 2b) + 6(b - 2c) = 0
a(c - 2b) = -6(b - 2c)
a = -6(b - 2c)/(c - 2b)

Since a, b, and c are non-zero and distinct, we can see that a, b, and c are in an arithmetic progression (A.P.) with common difference -6/(c - 2b).

Therefore, the correct answer is option A: 1/a, 1/b, 1/c are in an arithmetic progression (A.P.).
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If the system of linear equations2x + 2ay + az = 02x + 3by + bz = 0 and2x + 4cy + cz = 0,where a, b, c R are non-zero and distinct; has non-zero solution, thena)1/a, 1/b, 1/c are in A.P.b)a + b + c = 0c)a, b, c are in A.P.d)a, b, c are in G.P.Correct answer is option 'A'. Can you explain this answer?
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If the system of linear equations2x + 2ay + az = 02x + 3by + bz = 0 and2x + 4cy + cz = 0,where a, b, c R are non-zero and distinct; has non-zero solution, thena)1/a, 1/b, 1/c are in A.P.b)a + b + c = 0c)a, b, c are in A.P.d)a, b, c are in G.P.Correct answer is option 'A'. Can you explain this answer? for Defence 2024 is part of Defence preparation. The Question and answers have been prepared according to the Defence exam syllabus. Information about If the system of linear equations2x + 2ay + az = 02x + 3by + bz = 0 and2x + 4cy + cz = 0,where a, b, c R are non-zero and distinct; has non-zero solution, thena)1/a, 1/b, 1/c are in A.P.b)a + b + c = 0c)a, b, c are in A.P.d)a, b, c are in G.P.Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for Defence 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If the system of linear equations2x + 2ay + az = 02x + 3by + bz = 0 and2x + 4cy + cz = 0,where a, b, c R are non-zero and distinct; has non-zero solution, thena)1/a, 1/b, 1/c are in A.P.b)a + b + c = 0c)a, b, c are in A.P.d)a, b, c are in G.P.Correct answer is option 'A'. Can you explain this answer?.
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