Answer :
n/3 - 3 = 12
*add 3 to both sides
n/3 - 3 + 3 = 12 + 3
n/3= 15
*multiply 3 to both sides
n/3 * 3 = 15 * 3
n = 45
*add 3 to both sides
n/3 - 3 + 3 = 12 + 3
n/3= 15
*multiply 3 to both sides
n/3 * 3 = 15 * 3
n = 45