Question

if the length of a certain is decreased by 4 cm and width is increased by 3 cm a square with the same area as the origional rectangle would result find the permiter of the original rectangle

Answer 1

the length of the rectangle is decreased by 4 cm and the width is increased by 3 cm, length n breadth becomes equal (bcoz the result is a square)

L-4 = b + 3.

L = b+7. ***** eqn a

Given:

Area if square= Area of rectangle

(L-4)(b+3) = Lb

Lb + 3L - 4b -12 = Lb

3L - 4b -12 = 0

3L - 4b = 12

Substitute for L

3(b+7) - 4b = 12

3b + 21 - 4b = 12

21 - b = 12

b= 21-12

= 9

L = b+7

= 9 + 7

= 16

Perimeter= 2(L +b)

=2(16 + 9)

=2*25

=50 cm