(3x+2y)(2x-5y)-(x+y)(6x-7y)点用公式啊
x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8
先化简,后求值(x+5y)(x+4y)(x-y)(x+y),其中,x=-2又2/3,y=3/7,用公式计算
2(2x+3y)(3x+2y)-(6x-y)(2x-5y)
1.((y+2x)(-2x+y)+4(x+2y)^2)/3y 2.(2(x-y)^3-8(x-y)^2(x+y)+6y(
2(y-x)的平方-7(x-y)+6(x-y)-3(y-x)的平方
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
计算:(x-y)^7÷(y-x)^6+(-x-y)^3÷(x+y)^2
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
数学(x-y)^5*(y-x)^3*(x-y)^2
计算(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-x^y^7+y^8)(x^2+xy+y^2)
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
用平方差公式展开(-x+3y)(-x-3y) (-2+3x)(-2-3x)(1\3x-y)(-1\3x-y)(x+y+4