x+2y=3 xy=2 则x²+4y²=?
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知x-y=4xy,则2x+3xy-2yx-2xy-y
已知X/Y=2,则X²+2XY-3Y²/X²-XY+Y²=?
已知x²-3xy+4x=3,y²+xy-4y+7=0,则xy-1/2(x²+y²
A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²+3x-y,若x=
设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²-3x-y,若x
一.x-y=2,则x²-2xy+y²= 二.x-y=-1,xy=3,则x³y-2x
已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y
2x+y=0,求4x²+2xy(x+y)+y³
(-3x^y+2xy)-( )=4x^+xy
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
(x+3y)(x-y)-(x+y)^2 =x²-xy+3xy-3y²-x²-y²