Question

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?

Answer 1

answer C

Explanation:

Answer 2

x - y = 7...x = y + 7
3x - 2y = 8

3(y + 7) - 2y = 8 ...correct
3y + 21 - 2y = 8 <== here is the error...did not distribute correctly

answer is : step 3