Answer:
x = 9
Step-by-step explanation:
Perimeter of rectangle = 2(l+b) = 42
=> 2(x+3 + x)
=> 2 (2x + 3) = 42
=> 4x + 6 = 42
=> 4x = 42 - 6
=> 4x = 36
=> x = 36/4
=> x = 9
Hope it helps :)
Formula = (l + b) x 2= 42 so answer = x=9
l =x
b =x+3
( x+x+3) * 2 =42
2x +3 x 2 = 42
2x +3 = 42/2
2x +3 = 21
2x = 21 - 3 =18
x = 18/2
x=9
