Find the area of a rectangle with a width of x3 + 5x - 9 and a length of x2 + 8.

A = x⁵ + 13x³ - 9x² + 40x - 72

Step-by-step explanation:

The formula for the area of a rectangle is length X width, or A = lw.

Substitute the equations for the sides into the formula:

A = lw

A = (x² + 8) (x³ + 5x - 9) < = use the distributive property

A = x⁵ + 5x³ - 9x² + 8x³ + 40x - 72 < = collect like terms

A = x⁵ + 13x³ - 9x² + 40x - 72