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

equation 1: m = 8 + 2n
equation 2: 6m = 4 + 4n

step 1: −6(m) = −6(8 + 2n) [equation 1 is multiplied by −6.]
6m = 4 + 4n [equation 2]
step 2: −6m = −48 − 12n [equation 1 in step 1 is simplified.]
6m = 4 + 4n [equation 2]
step 3: −6m + 6m = −48 − 12n + 4n [equations in step 2 are added.]
step 4: 0 = −48 − 8n
step 5: n = −6

in which step did the student first make an error?
step 3
step 5
step 4
step 2