(08.05)
the work of a student to solve a set of equations is shown below:

equation 1: m = 6 + n
equation 2: 2m = 8 + 8n

step 1:
−2(m) =
−2(6 + n)

2m =
8 + 8n

step 2:
−2m =
−12 − 2n

2m =
8 + 8n

step 3:
−12 − 2n =
8 + 8n

step 4:
−20 =
10n

step 5:
n =
−2

in which step did the student first make an error?

step 2
step 3
step 4
step 5