1.(x+y)(x-y)(x^2+y^2)=（ ）2.若x^2+mx+1/4 是一个完全平方式,则m的值为（ ）3.12x^7y^6z^5÷（ ）=4x^3y^3z^34.若(x+6)(x-7)=x^2+mx+n,则m=( ),n=( ）5.已知x+1/x=3,则x^2+1/x^2=

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 化简y(x+y)+(x+y)(x-y)-x^2 (x+y)(x-y)-(x-y)^2如题 (x+y)(x-y)-(x-y)^2 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) 因式分解x(x+y)(x-y)-x(x+y)^2 [(x-y)^2-(x+2y)(x-2y)]/y 计算:y-x分之x+y+x-y分之y-y-x分之2x-y x^2(x-y)+(y-x) x(x-y)2-(y-x)3 【(x-y)^2+(x+y)(x-y)】除以 2x [(x-y)²+(x+y)(x-y)]除以2x 1.（x+2)^2-(x+y)^32.(x-y)^2-(x-y)^33.(x-y)^2-(y-x)^3 [2/3x-2/x+y(x+y/3x-x-y)]/x-y/x 化简：{2/3x-2/(x+y)[(x+y)/3x-x-y]}/(x+y)/x 计算2/3x-2/x+y(x+y/3x-x-y)/x-y/x 化简3x-2/(x+y)[(x+y)/3x-x-y]÷(x-y)/x 化简：[(x+y)(x-y)(x+y)^2-2y(x-2y)](-2y) 谢谢! 计算：[(x+y)(x-y)-(x-y)^2+2y(x-y)]/(-2y)