Respuesta :

Substitution method can be applied in four steps.Solve one of the equations for either x = or y = .Substitute the solution from step 1 into the other equation.Solve this new equation.Solve for the second variable. ...Step 1: Solve one of the equations for either x = or y = .  - Google.
for an example   D+2=4  then it says D=2 you substitute  the 2 for the d so 2+2=4