very hard.. pls don't answer if you don't understand it fully. i will report and delete your answer if its wrong.

Which ordered pair (c,d) is a solution to the given system of linear equations- c+2d=13 -9c-4d=-15

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 =

Rewrite 9 log, x2 in a form that does not use exponents. 9log, x = log, x