Please it's urgent I really need answers

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 =

Valentina is subtracting from . she finds the lcd to be 15y2. what is valentina's next step?

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?