Somebody please help me thansk

Pls! does anybody know a shortcut for answering these types of questions in the future?

An architect is designing a water fountain for a park she uses the given function to model the water jet flowing from the fountain nozzles where h(x) gives the height of the water jugs in feet x feet from the starting point h(x)=-1/20x+x+15

If square root x = -7, then x= -49 true or false