x2-4y2-3xy+y+x

x2-4y2-3xy+y+x 计算(x+y/x-y + 4xy/y2-x2)(x2-9y2)/（x2+2xy-3y2） 2x2+xy-3y2+x+4y-1因式分解 因式分解x2-4y2-3xy+y+x (x-y)(x2+xy+y2) (x+y)(x2-xy+y2) 4x2-y2/x2-2xy+y2 +(2x-y)/2x2-2xy 解方程组 ｛3x2-y2=8 {4x2+12xy+9y2=1 {x2+2xy+y2-4=0 x2+xy+y2=4 4x2-9y2=0 x2-2xy+y2-1=0还有{x2+y2=4xy-y2+4=0x2-----x的平方 y2------y的平方 还有{2x-3y=12x2-3xy+y2-4x+3y-3=0 (x+√(x2+2011))(y+(√y2+2011))=2011,x2-3xy-4y2-6x-6y+58 已知实数x,y满足x2+xy+y2=3,则x2-xy+y2的最小值 因式分解：3x2+5xy-2y2+x+9y-4 x2+x-(a2-a) 3x2+4xy-y2 x,y,a后面的2表示平方 x2-2xy+y2=4 x2+y2-x-y=6 解不等式x2-2xy+y2=4 x2+y2-x-y=6 解不等式 已知x2+4y2+x2y2+1=6xy,则(x4-y4)/(2x2+xy-y2)*(2x-y)/(xy-y2)/(x2+y2/y)2= 因式分解 2x2+xy-y2-4x+5y-6 x2-y2+a2-b2+2ax+2by 3x2+5xy-2y2+x+9y-4 b4-2b2-82x2+xy-y2-4x+5y-6x2-y2+a2-b2+2ax+2by3x2+5xy-2y2+x+9y-4b4-2b2-8 计算3xy/x2次方-4y2次方÷xy/x+2y 已知x+y=4,xy=2,求x2+y2+3xy的值. 因式分解3x2+xy-y2+x+9y-43X^2+XY-Y^2+X+9Y-4 x3-y3-x2+2xy-y2 因式分解还有：(2) x2+2xy-3y2+3x+y+2(3) 6x2-7x-4（实数范围内）