Answer:
6/7 ab
Step-by-step explanation:
72 a^5 b^3
-------------------
84 a^4 b^2
Separate by like terms
72/84 Divide by 12 on top and bottom = 6/7
a^5 /a^4 = a^(5-4) = a
b^3/b^2 = b^(3-2) = b
