Power: 3 ^ 2 = 9
Subtract: 8 - 2 = 6
Multiple: 6 * 4 = 24
Add: 9 + 24 = 33
Subtract: 33 - 63 = 331 - 63 = 33 · 31 · 3 - 63 = 993 - 63 = 99 - 63 = 933 = 31
The common denominator you can calculate as the least common multiple of the both denominators - LCM(1, 3) = 3