Probably y = 8x. 56 = 8(7), so that works. Without more data, I couldn't say if it could be something else, so that's what I go with.
It’s the third answer
(2x + 5) x ( 3x -4)
The answer is 4√6 4√x
Sorry if that looks confusing but it means small 4, big 6 and then small 4
