Aptitude Algebraic Expressions Test Paper 1

Answer: D

Explanation:

Adding 2 to the L.H.S and R.H.S of the equation:

x²+2+=34+2[∵(a+b)²=a²+b²+2ab]

(x+)²= 36

(x+)= +6,-6

Answer: A

Explanation:

16x+=8

=8

16x²+1=8x

=>16x²+1-8x=0

=>(4x-1)²=0

=>x =

Answer: C

Explanation:

The required equation is:
x²-(sum of roots)x+product of roots=0
=>x²-(4+5)x+4 ×5=0
=>x²-9x+20=0

Answer: A

Explanation:

Let the sides of the rectangle be x and y meters respectively. Then
2x + 2y = 48
2 (x+y) = 48
x+y = 24
y = 24 -x

We have, xy = 135
So, x (24 - x) = 135
24x - x² = 135
x² -24x + 135 = 0
x² - 9x - 15x + 135 = 0
(x-9) (x -15) = 0
x = 9 m or 15 m
So, when x = 9m, y = 24 - 9 = 15m
And when x = 15, y = 24 -15 = 9 m
So, the sides of rectangle are 15m and 9m.

Answer: A

Explanation:

(x + 3) (x - 3) = 160
x² - 9 = 160
x² = 169
x = +13, - 13