Hey i need with this it's surds√3×√6

Which shows the correct solution of the equation 1/2a+2/3b=50, when b=30?

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 =

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10