Question

How can you determine whether (3,5) is a solution to this equation 3x-y=4?

Answer 1

You would plug in the coordinate for the x and y values, like so:
3(3) - 5 = 4
And then simplify:
9 - 5 = 4
4 = 4
Looks like (3, 5) is a solution to the equation!

Answer 2

3x-y ? 4
3(3) - 5 = ? 4
9 - 5 ? 4
4 = 4

Yes
(3,5) is a solution to this equation 3x-y=4