HELP CHECK THIS

The work of a student to solve a set of equations is shown:


Equation A: y = 15 − 2z

Equation B: 2y = 3 − 4z



Step 1: −2(y) = −2(15 − 2z) [Equation A is multiplied by −2.]

2y = 3 − 4z [Equation B]

Step 2: −2y = 15 − 2z [Equation A in Step 1 is simplified.]

2y = 3 − 4z [Equation B]

Step 3: 0 = 18 − 6z [Equations in Step 2 are added.]

Step 4: 6z = 18

Step 5: z = 3



In which step did the student first make an error?

Step1

Step 2

Step 3 <<<<<

Step 4