One equation in a system of equations is y = 4x + 5. Which equation below would have to be the second equation so that the system has (1, 9) as its only solution?

Question

One equation in a system of equations is y = 4x + 5. Which equation below would have to be the second equation so that the system has (1, 9) as its only solution?

Answer 1

y = 4x+5

and

y =-4x +13

have a unique solution (1,9)

but there are an infinite number of other equations that will also work