(1).x^2-8xy+7y^2
xy/3x+2y=1/8 xy/2x+3y=1/7
因式分解:8(x-2y)-x(7x+y)+xy.
1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)
(x+y-2xy)(x+y-2)+(1-xy)²
解方程组xy/3x+2y=1/8, xy/2x+3y=1/7
(1) -3X^-2XY-8XY-(-5Y^2)-2X^2-Y^2
x+y=8,xy=-2,求(5xy+4x+7y)+(6x-3xy)-(4xy-3y)的值
计算3xy[2xy-x(y-2)+x-1]
(xy-x^2)乘以(xy)/(x-y)
已知1/x-1/y=2,求3x+7xy-3y/2x-3xy-2y
已知1/x+1/y=8,求2x-3xy+2y/x+2xy+y的值
已知1/x-1/y=5 求分式-x+xy+y/2x+7xy-2y