Question

Simplify 15 to the 18th power over 15 to the 3rd power.

Answer 1

(15^18) / (15^3)

If the exponents you're dividing have the same base, you subtract them.
18 - 3 = 15

15^15

Answer 2

$\cfrac{15^{18}}{15^3} = 15^{18-3}=15^{15}$