(n/3) + 5 - 8 = 2
First add the constants (+5 and -8) on LHS.
(n/3) - 3 = 2
Transfer -3 to RHS, by changing its sign.
n/3 = 2 + 3
Now add the constants (2 and 3) on RHS.
n/3 = 5
Transfer 3 to RHS by changing division to multiplication
n = 5 × 3
Finally multiply the constants (5 and 3) on RHS
n = 15