x²-xy-6y²-2x+11y-3;2x²-xy-6y²+3x+8y-2; 3
x²-xy-6y²-2x+11y-3;2x²-xy-6y²+3x+8y-2; 3
x²-xy-6y²-2x+11y-3; 2x²-xy-6y²+3x+8y-2;
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
计算3x/8y×16y²/27x² (2xy-x²)÷x-2y/xy 2x-6/x
已知x/y=2,求x²-xy+3y²/x²+xy+6y²的值
急![(3x+y)²-3(3x-y)(x+y)-(x-3y)(x+3y)]÷(2xy)
计算3x[xy-2x(1/y-x/3]+3y(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
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy
先化简,再求值:{xy(x²-3y)+3xy²}(-2xy)+x³y²(2x-y