Question

Is (1,-1) a solution of y=3x+2

Answer 1

In order to check a solution, just plug in the coordinates.  The 1 is x, and the -1 is the y.  Just plug the numbers in and see if it works out:

y = 3x + 2
(-1) = 3(1) + 2
-1 = 5

-1 is NOT equal to 5, so (1, -1) is NOT a solution of y = 3x + 2.