Question

solve the system of equation using substitution
y=2x+3
y=3x+1

Answer 1

2x+3 = 3x+1

You're almost done.

Answer 2

Take either one of the equations, y=2x+3 for example, and put the 2x on the other side.
Then you have y-2x=3.
Now you have to substitute what you know into this equation. You know that y=3x+1 from the other equation. Your new equation should look something like 3x+1-2x=3.
You can now solve fro the x and then plug the x value you get in for the x in either one of the original equations and solve for y.