Mathematics

Cassie Bolton

20 May, 22:41

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

Equation A: y = 4 - 2z

Equation B: 4y = 2 - 4z

Step 1: - 4 (y) = - 4 (4 - 2z) [Equation A is multiplied by - 4.]

4y = 2 - 4z [Equation B]

Step 2: - 4y = 4 - 2z [Equation A in Step 1 is simplified.]

4y = 2 - 4z [Equation B]

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

Step 4: 6z = 6

Step 5: z = 1

In which step did the student first make an error?

Step 1

Step 3

Step 4

Step 2