1. (X²y¯1 : y³x⁴) ¯² 2. (2ab²)³ (ab)¯½ : (ab)⅔

1.(X²y¯1 : y³x⁴) ¯²
=> x^-4 y^2 : y^-6 x^-8
=> x^8-4 y^6+2
=> x^4 y^8

2. (2ab²)³ (ab)¯½ : (ab)⅔
=> (2ab²)³ : (ab)^2/3-1/2
=> 8(ab²)^3 : (ab)^4-3/6
=> 8(ab²)^3 : (ab)^1/6
=> 8(ab²)^3-1/6
=>8(ab²)^17/6