Rewrite 18x power of 4 y power of 4 − 36x power of 3 y power of 4 using a common factor.

2x power of 4 y power of 4 (9 − 18x)
2x power of 3 y power of 3 (9y − 18x)
9x power of 3 y power of 3(2x − 4y)
9x power of 4 y power of 3(2 − 4y)