因式分解1.x^2-y^2-z^2-2xy-2x+12.ab(c+d)(c-d)+cd(a+b)(a-b)3.1-xy(1-xy)-x^3y^3
热心网友
因式分解1.x^2-y^2-z^2-2xy-2x+1原式＝x^2 -2(y+1)x -y^2-z^2 +1看作关于x的二次三项式，用 x^2+px+q=(x-x1)(x-x2)公式去作。2.ab(c+d)(c-d)+cd(a+b)(a-b)原式＝abc^2-abd^2+cda^2-cdb^2 = ac(bc+ad)-bd(ad+bc)=(ac-bd)(bc+ad)3.1-xy(1-xy)-x^3y^3 原式＝1-xy+(xy)^2 -(xy)^3=(1-xy)+(xy)^2*(1-xy)=(1-xy)[1+(xy)^2]
热心网友
1.x^2-y^2-z^2-2xy-2x+1原式＝x^2 -2(y+1)x -y^2-z^2 +1 ＝(x-1-y-z)(x-1+y+z)2.ab(c+d)(c-d)+cd(a+b)(a-b)原式=abc^2-abd^2+cda^2-cdb^2 = ac(bc+ad)-bd(ad+bc) =(ac-bd)(bc+ad)3.1-xy(1-xy)-x^3y^3 原式＝1-xy+(xy)^2 -(xy)^3=(1-xy)+(xy)^2*(1-xy)=(1-xy)(1+x^2y^2)