(7y-2x)-(7x-4y)
(7y-2x)-(7x-4y)
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)
x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8
因式分解(X+2Y)(3X-7Y)平方-4(X+2Y)(X+Y)平方
化简,亲快啊啊急!(3x-2y)(7x-y)-(4x+3y)(x-y)
(x-4y)分之(3x)+(4y-x)分之(x+y)-(x-4y)分之(7y)
计算:1/(x-y)-1/(x+y)-2y/(x^2+y^2)-4y^3/(x^4+y^4)-8x^7/(x^8+y^8
先化简在求值 (x+5y)(x+4y)-(x-y)(x+y),其中,x=-2又2/3,y=3/7
化简求值(x+5y)(x+4y)-(x-y)(x+y),其中x=一又2/5,y=-1/7
化简2(2X-7Y)(7Y+2X)+X^2-(-4X+5Y)(-5Y-4X)
已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y
化简[21x^5y^7-28x^7y^4+7y(2x³y²)²]÷(-7x^5y^4)