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