2x+3y=5(1)7x+6y=10(2)求xy的值
x+y=8,xy=-2,求(5xy+4x+7y)+(6x-3xy)-(4xy-3y)的值
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+x(xy+y)的值
已知xy^2=-6,求-xy(x^3y^7-3x^2y^5-y)的值
已知xy²=-6,求xy(x^3y^7-3x^2y^5-11.5y)的值
已知1/x-1/y=5,求分式y+xy-x/2x+7xy-2y的值.
已知1/X-1/y=5,求分式(y+xy-x)/(2x+7xy-2y)的值
已知1/x+1/y=5,求x+2xy+y/2x-3xy+2y的值
已知:1/X+1/Y=5,求 2x-3xy+2y/x+2xy+y的值,
已知1/x-1/y=3,求x-2xy-y/5x+3xy-5y的值
1/x+1/y=5,求2x-3xy+2y/x²+xy+y的值
已知1/X-1/Y=-2,求3X-5XY-3Y/-X+3XY+Y的值
若1/x-1/y=3,求5x+2xy-5y/x-4xy-y的值