Plz me its very confusing i need plz can u

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

65% of students in your school participate in at least one after school activity. if there are 980 students in you school, how many do not participate in an after school activity?

Someone answer asap for ! michele pushes a box d meters across a floor. she uses a force f, in newtons, to push the box. she pushes the box for t seconds. the formula p = fd/t calculates the power, p, in watts, that it takes for michele to complete the task. solve the formula for d.