These equations have two solutions, one for solving for each variable. There is a solution for solving for x, and one for y. For both of these equations,
Use the elimination method to solve the system of equations. Move the terms like so. As you can see I kept the first equation the same but multiplied the second equation by -3.
3x = -12y + 15
-3x = -12y - 15
Now add. 3x and -3x cancel; so does 15 and -15.
0 = -24y
Divide by -24. 0 div'd by -24 is equal to 0.
y = 0
Substitute y into the second equation.
x + 4(0) = 5
x + 0 = 5
x = 5
You've got x = 5 and y = 0; these are two solutions to the system of equations.