Solve the system of equations -2x-y=-5 and 3x-4y=-42 by combining the equations. when you answer can you also show the steps you used to get the answer? thanks

Ary throws a plastic disc to her friend, which her friend catches six seconds after mary throws it. the table shows the height of the disc at one-second intervals. assuming that the throw represents projectile motion, what are the missing values in the table? a = 5, b = 3 a = 4, b = 0 a = 4, b = 3 a = 5, b = 0