Simplifying the top:
(2* a^3 * b^5)^2 * (6ab)
4* a^6 *b^10 * (6ab)
24 *a^7 * b^11
so we have
(24 *a^7 * b^11) / (-3* a^5 *b)
immediately we can simplify 24 and -3
(-8 *a^7 * b^11) / ( a^5 *b)
a^7 and a^5 can cancel into just a^2
(-8 *a^2 * b^11) / (b)
b^11 and b cancels to b^10
-8 *a^2 * b^10
so that is your answer:
-8
