Help pls this is timed

Awater truck is filling a swimming pool. the equation that represents this relationship is y=19.75x where y is the number of gallons of water in the pool and x is the number of minutes the truck has been filling the pool.

Using elimination, what is -4x+2y=-12 4x+8y=-24

Given: m zade = 60° and m2cdf = (3x + 15) prove: x = 15