I haven't done this in a long time, somebody PLEASE help!

Which expression is equivalent to (3^2)^-2 a.-81 b.-12 c.1/81 d.1/12

Each month, a shopkeeper spends 5x + 14 dollars on rent and electricity. if he spends 3x−5 dollars on rent, how much does he spend on electricity? for which value(s) of x is the amount the shopkeeper spends on electricity less than $100? explain how you found the value(s).

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')