How do you do this ? Anyone who know how and can explain this

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

The circumference of a redwood tree trunk is 20π ft, and it is 100 ft tall. what is the approximate volume of the redwood tree trunk? 1,000π ft3 10,000π ft3 4,000π ft3 40,000π ft3

In a young single person's monthly budget, $150 is spent on food, $175 is spent on housing, and $175 is spend on other items. suppose you drew a circle graph to represent this information, what percent of the graph represents housing?