Question

The length of a rectangle is 15 cm more than its width. The perimeter is 150 cm. Find the dimensions of the rectangle.

Answer 1

let the breadth=x
    the length  =x+15
given perimeter= 150
we know 
Perimeter of rectangle = 2(l+b)
                          150 = 2( x+ x+15)
                           75 = 2x +15
                            60 = 2x
                             30=x 
therefore breadth = 30 cm 
              length   = 30 +15  = 45 cm

check 
150 = 2( 45+30)
150 = 2(75)
150 = 150 
LHS=RHS
hence prooved

Answer 2

Let the breadth = x
 Length  = x + 15
Perimeter = 150
We know 
Perimeter of rectangle = 2 ( l + b )
                          150 = 2 ( x+ x + 15)
                           75 = 2 x + 15
                            60 = 2 x
                             30 = x 
Therefore
breadth = 30 cm 
length   = 30 +15  = 45 cm

Foe Check.
150 = 2 ( 45 + 30 )
150 = 150

L.H.S = R.H.S

HENCE PROVED.