已知X^2-2XY=47,3XY+4Y^2=-19,则3X^2+8Y^2=多少?
已知x-y=4xy,则2x+3xy-2yx-2xy-y
由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少?
若x+y分之xy=2,则-x+3xy-y分之3x-xy+3y=多少?
已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值!
已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y=
已知xy/x+y=2,则代数式3x-5y+8y/-x+3xy-y的值
已知X^2-2XY=47,3XY+4Y^2=-19,则3X^2+8Y^2=多少?
已知:x-y=1,xy=-2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知2x+xy=10,3y+2xy=6.求4x+8xy+9y=?
已知y-x=3xy,则代数式2x-14xy-2y分之x-2xy-y的值为多少?
(-3x^y+2xy)-( )=4x^+xy