.This is another one of those problems that I kinda get the idea of how to do it but then just can't think of anything else. So, to the problem.

Function

Line

is this 3x-y+1 = 0 ?

From here we know that since

Then I made

To get the value of x.

x = -1 also

Now I go back to the given line and plug in:

3(1) + 1 = 4, not 5