1) 18bc
-----------
24c
2) 25a^2y
---------------
15by
3) 24a^3
-------------
6ac
4) 27x^2y
--------------
21xy^3
5) -2a^6b^3
-----------------
a^3b^5
6)x^7y^4
--------------
x^5y^8
7) 42m^3n^5
-------------------
35mn^5
8) 75p^4q
---------------
150p^4q