Question 332563
The width of a rectangle is 5cm less than half its length. Its area is 72cm^2. What is the length and width of the rectangle?
.
Let x = length of rectangle
then
x/2 - 5 = width
.
x(x/2 - 5) = 72
multiplying both sides by 2:
x(x - 10) = 144
x^2 - 10x = 144
x^2 - 10x - 144 = 0
(x-18)(x+8) = 0
x = {18, -8}
Tossing out the negative solution leaves:
x = 18 cm (length)
.
width:
x/2 - 5 = 18/2 - 5 = 9 - 5 =  4 cm (width)