[3﹙x-y﹚^4 ﹙x+y﹚^5 -6﹙x-y﹚^3 ﹙x+y﹚^4 ]÷[3﹙x-y﹚²﹙x+y﹚³]等于多少

题目

[3﹙x-y﹚^4 ﹙x+y﹚^5 -6﹙x-y﹚^3 ﹙x+y﹚^4 ]÷[3﹙x-y﹚²﹙x+y﹚³]等于多少

答案

=(x-y)^2(x+y)^2-2(x-y)(x+y)=(x^2-y^2)^2-2(x^2-y^2)=x^4-2x^2y^2+y^4-2x^2+2y^2