y=(2x²+1)²y′=2(2x²+1)*(2x²+1)=2(2x²
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
已知x²+y²+5=2x+4y,求代数式(2x²-(x+y)(x-y))x((x+y-1)
[2x²-(x+y) (x-y)] [(-x-y) (y-x)+2y²] 其中x=1,y=2
[(y-2x)(-2x-y)-4(x-2y)²]*2y,其中x=1,y=2
化简求值 【2x²-(x+y)(x-y)][(x+y-1)(x-y+1)+1-2y],其中x=-1,y=-2
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
(X-Y)²+(3X-2Y)(2X+Y)-X(6X-Y),其中X=½,Y=1(先化简再求值)
已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y
1/2 x²y·( )=2x³y-x²y²
先化简,再求值:(3x-y)²+(3x+y)(3x-y),其中x=1,y=-2
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值