Question

the length of rectangle is 4 times its width.the perimeter is 150.find the dimension of the rectangle by matrix invetsion method

Answer 1

Given
l = 4b
perimeter = 2(l+b) = 150

2(4b+b) = 50
5b = 25
b = 5

l = 4b
l = 4×5
l = 20

Hence the dimension of the rectangle is 20 unit by 5 unit

Answer 2

Let the width be b
So length , l = 4b

Perimeter of a rectangle = 2(l +b)
2( 4b +b ) = 150
2( 5b) = 150
5b = 75
b = 15cm

l = 4 x 15 = 60cm

Therefore the dimension of rectangle is 60cm x 15cm