Which equation shows the substitution method being used to solve the system of linear equations?
the second answer choice. As you can see, they are replacing the 'x' in the first equation with the value of 'x' in the second. Think of the second equation as saying "x is the same as y+5", that's why they're equal. That means they're interchangeable. So you can substitute, or replace, the x in the first equation with y+5.