Genevieve wants to verify that Negative x is the simplified expression of One-fifth (5 x minus 20) minus one-half (4 x minus 8).

Which procedure can Genevieve follow to verify this?
Add One-fifth (5 x minus 20) minus one-half (4 x minus 8) and Negative x.
Put an equal sign between One-fifth (5 x minus 20) minus one-half (4 x minus 8) and One-fifth (5 x minus 20) minus one-half (4 x minus 8) and then solve for x.
Substitute 5 for the first x, substitute 4 for the second x, then evaluate.
Substitute 5 into the expression and evaluate.