A dolphin trainer is trying a new trick. He will jump upward from a spring board, through a suspended hula hoop 10 feet
above the water. If he can get an initial leap of 19ft/sec.
a) Should we move the hula hoop up or down, by how much?
b) How long is his hang time (how long is he in the air for?)

Given the system of equations presented here: 2x + 4y = 14 4x + y = 20 which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated? multiply the second equation by â’4 to get â’16x â’ 4y = â’80 multiply the second equation by â’1 to get â’4x â’ y = â’20 multiply the first equation by 2 to get 4x + 8y = 28 multiply the first equation by â’1 to get â’2x â’ 4y = â’14