(5x+7y-2)(5x-7y+2)化简是什么?急
化简求值(x+5y)(x+4y)-(x-y)(x+y),其中x=一又2/5,y=-1/7
解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7
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
3(x-y)-2(x+y)-5(x-y)+4(x+y)+3(x-y) 化简合并同类项
化简2(2X-7Y)(7Y+2X)+X^2-(-4X+5Y)(-5Y-4X)
1.已知x:y:z=4:5:7,求:(一)2x+3y+z/5z; (二)x+y/y+z 非常急,
化简,亲快啊啊急!(3x-2y)(7x-y)-(4x+3y)(x-y)
化简求值(x+2y)^2-(2x+y)(2x-y)-5y(y-x) 其中 x=1/3 y= -1/2
5(2x-7y)-(4x-10y)全过程
5x+2y=83x-y=7
合并同类项:-3x+2y-5x-7y