Question

which equation has (2, -1) as a solution
1. y=2x-1
2. y=x+3
3. y=x-3
4.y=-2x+1

Answer 1

You could plug the point into the equations and see which statement is true as a result.

Answer 2

for example (2,-1)=(x,y)
replace x with 2 and y with -1
looking at equation 1)
is this true? : -1=2(2)-1

Answer 3

do this for each equation until you get the statement is true when plugging in 2 for x and y with -1