因式分解-81+18(X+Y)-(X+Y)^2
问题描述:
因式分解-81+18(X+Y)-(X+Y)^2
答
=-[(X+Y)^2-18(X+Y)+81]
=-(X+Y-9)^2
因式分解-81+18(X+Y)-(X+Y)^2
=-[(X+Y)^2-18(X+Y)+81]
=-(X+Y-9)^2