计算 当x=0.5 y=2时(3xy-2x^2+0.5y^2)(3xy+2x^2-0.5y^2)的值
计算:3xy[2xy-x(y-2)+x]
计算 当x=0.5 y=2时(3xy-2x^2+0.5y^2)(3xy+2x^2-0.5y^2)的值
已知x-y=4,xy=-2,求代数式(2x+3y-2xy)-(x+4+xy)-(3xy+2y-2x)的值
当x=2,y=-1时,求代数式(x+y)(x-y)+(x-y)²-(x²-3xy)的值
已知xy=2,x-y=3,求(x+y)(x-y)-y^2-(6x^2y-2xy^2)/2y的值.
已知xy=-2,x-y=3,求(x+y)(x-y)-y平方+(x-y)平方-(6x2y-2xy平方)/2y的值
(1)当1\x-1\y=3时求2x+3xy-2y\x-2xy-y的值
当x-3y=0时,求(x二次方+xy+2y二次方)÷(x二次方-xy+y二次方)的值
当x-y=1时,求x^4-xy^3-x^3y-3x^2y+3xy^2+y^4的值
(x+2y-3y)- (-2x-y+xy ) 其中x+y=0.5 xy等于-0.5
初中数学分式已知x/y=2,求(x*x-xy+3y*y)/x*x+xy+6y*y的值
计算4xy+(x-2y)的平方+(x+3y)(3y-x)