Exponents: Power rule (a^x)^y = a^(x * y)

Lessons

1. prove: $(3^5)^2 = 3 ^{(5\cdot 2)}=3^{10}$
2. simplify: $(2a^5b^{-4}c)^3$
3. simplify: $(\frac{3a^4}{5b^{10}c^7})^2$