Question 26201
Subtract the exponents.
That means for the "a's" you have a/a^4 = 1/a^(4-1)=1/a^3
For the "b's" you have b^7/b^9 = 1/b^(9-7)=1/b^2
So, the solution is 1/[a^3b^2]
Cheers,
Stan H.