Ernesto tried to determine the solution for the system of equations using substitution. his work is shown below. x – y = 7 3x – 2y = 8 step 1: x = y + 7 step 2: 3(y + 7) – 2y = 8 step 3: 3y + 7 – 2y = 8 step 4: y + 7 = 8 step 5: y = 1 in which step did ernesto make the first error? step 1 step 2 step 3 step 4