Question

The width of a rectangle is 4 inches less than its length. The perimeter of the rectangle is 12 inches what is the width

Answer 1

Let the length is x and the width is y
x - y = 4 .........(1) 2x + 2y = 12
x + y = 6........(2) 
by adding 1 and 2 
2x =10 , x = 5 
y = 1 inch