Question

a square poster of length 3x is going to have a square painting centered on it. The length of the painting is 2x. the area of the poster not covered by the painting will be painted black. what is the area of the poster that will be painted black?

Answer 1

One way to solve this is to look at the size of the poster, and then subtract the size of the picture so you have the area that needs to be painted left.

Area of square poster - 3x × 3x = 9x^2
Area of painting - 2x × 2x = 4x^2

9x^2 - 4x^2 = 5x^2

The area is 5x^2