原式=[(2x-y)-3]²=(2x-y)²-6(2x-y)+9=4x²-4xy+y
原式=[(2x-y)-3]²=(2x-y)²-6(2x-y)+9=4x²-4xy+y
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
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
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
解方程x²-2xy+y²=9,x²+4xy+4y²+x+2y=2 2x-1/y=
若A=2x²-4xy-2y²-2x+2y,B=4x²-6xy+2y²-3x-y.
1.设A=2x²-3xy+y²+x-3y,B=4x²-6xy+2y²+4x-y,
设A=2x²-3xy+y²+x-3y ,B=4x²-6xy+2y²+4x-y ,
设A=2X²-3xy+y²-x+2y,B=4x²-6xy+2y²-3x-y,若|