Important Questions: Algebraic Expressions - Class 7 MCQ

adding above 3 equation we get
2x+2y+2z=24
2(x+y+z)=24
⇒ x+y+z = 12

3 formulae with the three unknowns can be formed from the given expression.

(3a + 2b) − (−2a − 5b)
= 3a + 2b + 2a + 5b = 5a + 7b

Area of the path along length = l×w
Area of the path along breadth = l×w
The common area of the paths = w²
∴ Total area of the path = lw+lw−w² = (l+b−w)w

Sum of units digit (x) and tens digit (x + 3) is x + x + 3 = 2x+3.

As per question,m is divided by 5 and add to 8 gives 8+m/5​.

And is equal to 3m subtracted from 4 i.e. equal to 4−3m.

Then 4−3m=8+ m/5​

⇒20−15m=40+m

⇒20−40=m+15m

⇒−20=16m

⇒m= −5/4​

just put x=-2 in the expression x+2
-2 + 2 = 0

perimeter=sum of all sides
               =(9y-x)+(2x-y-1)+(3x-2)
               =8y+4x-3

⇒ C(x−b) = x−a
⇒ x = 

The correct option is Option B. 

(i)-(b) : 4m²p and 4mp² are unlike terms

(ii)-(a) : 5 - 3t is a binomial 

(iii)-(d) : -7x, 5/2x are like terms

(iv)-(c) : 1 + x + x² is a trinomial

2−6x + 4a−3b
2-6(3)+4(-1)-3(-2)
2-18-4+6
8-22
-14

a³−2a² + 4a − 5 −(−a³ − 8a + 2a²+5)=a³ − 2a² + 4a − 5 + a³ + 8a - 2a²-5
=2a³ − 4a² + 12a − 10

+ (a² + b³ + c³)

Substitute the given values in the expressions and evaluate. 

a³−b³ = 3³−2³ = 9−8 =1 

z³−3 (z−10) =10³−3(10−10) 

=10³ − 0 =1000 

x²+2x+1 = (−1)² + 2(1)+1 

= 1−2+1 = 0

x(y−z) − y(z−x) − z(x−y)
= xy − xz − yz + xy − zx + yz
= 2xy − 2zx = 2x(y−z)