I need help on my math hw pls :(

Which math sentence can be used to determine if the triangle is a right triangle?

How much money does ron have left each month after his fixed expenses? ron graduated from college five years ago. he recently bought a house, but shares it with a housemate who pays him $800 a month for rent and utilities. ron is putting a budget worksheet together so he will have a better idea of where his money is going and where he can save. enlarge

Which of these lines passes through the point (1,-1) and has a slope of -3?