Question

The length of a rectangle plus its width is 20 cm. the area is 36 square cm. what are the length and width of the rectangle?

Answer 1

The area is the product of length and width, so you want factors of 36 that add to give 20.
36 = 1*36 = 2*18 = 3*12 = 4*9 = 6*6
The factors that sum to 20 are 2 and 18.

The rectangle is 2 cm wide and 18 cm long.