计算 x²-4y²/x²+2xy+y²÷x+2y/2x²+2xy
问题描述:
计算 x²-4y²/x²+2xy+y²÷x+2y/2x²+2xy
答
(x²-4y²)/(x²+2xy+y²)÷(x+2y)/(2x²+2xy)
=[(x-2y)*(X+2Y)]/(X+Y)^2 ÷(x+2y)/[2x*(x+y)]
=[(x-2y)*(X+2Y)]/(X+Y)^2*[2x*(x+y)]/(X+2Y)
=(X-2Y)*2X/(X+Y)