Use full sentences to describe why the product of x^3 and x^7 is x^10

x^3 is a product of three factors of x: x * x * x.

x^7 is a product of seven factors of x: x * x * x * x * x * x

When you multiply x^3 by x^7, you end up with a product of 10 factors of x:

x * x * x * x * x * x * x * x * x * x

A product of ten factors of x is x^10.