Answer: If you need to see a systematic solution, let the 2 numbers be n and n + 2.
n(n + 2) = 63
n2 + 2n - 63 = 0
(n - 7)(n + 9) = 0
n = 7 or -9
If n = 7, then n + 2 = 9
If n = -9, then n + 2 = -7
This is based on knowledge of composite numbers: 7 times 9 = 63.
The only other pair of numbers satisfying this is -7 and -9
A bit confusing but hopes that helps out somewhat