When adding two rational numbers what will the sign be if both numbers are negative?

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

The graph shown is the graph of which function?

Aball is thrown from a height of 139 feet with an initial downward velocity of 15 ft/s. the ball's height h (in feet) after t seconds is given by the following. h=139-15t-16t^2 how long after the ball is thrown does it hit the ground? round your answer(s) to the nearest hundredth. (if there is more than one answer, use the "or" button.) t =