When you are multiplying 2 numbers with exponents, you need to add the exponent. When you multiply an exponent with an exponent, you multiply them.
So, (3^2 x 7^4) ^9 First multiply the base and add exponents = ( 21^6) ^9 = 21 ^6x9 21^54 The same rule applies for variables, just pretend there is an imaginary 1.
