algebra question Add and subtract as indicated. -7/a2b2 + 5/ab - 9/a5b5 -7/a2b2 + 5/ab - 9/a5b5 = Solution -7/a^2b^2 +5/ab -9/a^5b^5 = (5a^4b^4 -7a^3b^3 -9)/a^5b^5 if we put z=ab ==>(5z^4-7z^3-9)/z^5 .