The unknown number . . . . . (z)
The sum of the unknown number and 22 . . . . . (z + 22)
The sum of the unknown number and 22
divided by the same unknown number . . . . . . . (z + 22) / z
You said that quotient is 12. (z + 22) / z = 12
Multiply each side by 'z' : (z + 22) = 12 z
Subtract 'z' from each side: 22 = 11 z
Divide each side by 11 : 2 = z .
