hi there. i was wondering if any one could explain to me how to put this equation:

2^n * 8^n /2^2n * 16 in the form of 2^(an+b) the book says the answer is 2^(2n-a) i just cant work out hoe to solve it.

another equation i need help with is:

write 2^-x * 3^-x * 6^2x * 3^2x * 2^2x as a power of 6, the book says the answer is 6^3x but again i cant work out how to get that.

it would be great if someone could give me a hand and show me how to solve these types of equations. thnx heapz.