Question

A rectangle is 10 cm long and is 8 cm wide. When each side is increased by x cm, its perimeter is doubled. Find the equation in x and hence find the area of the new rectangle.

Answer 1

Perimeter of Rectangle
= 2(l+b)
= 2(10+8)
= 2(18)
= 36 cm

Now New Rectangle,

Length= 10+x
Breadth= 8+x

Perimeter of new Rectangle = Double Of Perimeter of 1 st rectangle

=2(l+b)=2x36cm
=2[(10+x)+(8+x)] = 72
=2(80+10x+8x+x^2)= 72
=2(80+18x+x^2) = 72
=80+18x+x^2 = 36
=x^2+18x+44=0

This Is the Equation

Find The Area Of New Rectangle yourself I'm Tired Now....
Hope This Will Help You......