Question

The width of a rectangle is the length minus 7 units. The area of the rectangle is 8

units. What is the length, in units, of the rectangle?

Answer 1

Area = length x width

Length = x

Width = x - 7

Area = 8

8 = (x)(x - 7)

8 = x^2 - 7x

x^2 - 7x - 8 = 0

Use the quadratic equation or factor (factoring is shown):

(x - 8)(x + 1) = 0

x - 8 = 0

x = 8

x + 1 = 0

x = -1

Since length is always a scalar quantity, or is always positive, the length is 8 units.

Length = x = 8 units

Width = x - 7 = 1 units

Hope this helps!! :)