(x^2+xy)/(x^2-xy)÷(x+y)÷[xy/(x^2-xy)]=(x^2+xy)/(x^2-xy)×[1/(x+y)]×[(x^2-xy)/xy]=[(x^2+xy)(x^2-xy)]/[(x^2-xy)(x+y)xy]=(x^2+xy)/[(x+y)xy]=[x(x+y)]/[(x+y)xy]=1/y
上图的式子可化简为x分之一，只要你告诉结果就等于告诉x的值！
