1.3x-y+2(y^-x^)-2(-x^+2y^),选一组你喜欢的数代替x、y的值.2.试着比较有理数a与1/a的大小(a不等于0).3x-y+2(2y^-x^)-2(-x^+2y^),选一组你喜欢的数代替x、y的值。错了，少了2。2y^是y的2次方，其他都是2次方

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 化简y(x+y)+(x+y)(x-y)-x^2 因式分解x(x+y)(x-y)-x(x+y)^2 (x+y)(x-y)-(x-y)^2如题 (x+y)(x-y)-(x-y)^2 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) x^2(x-y)+(y-x) x(x-y)2-(y-x)3 计算:y-x分之x+y+x-y分之y-y-x分之2x-y 【(x-y)^2+(x+y)(x-y)】除以 2x [(x-y)²+(x+y)(x-y)]除以2x [2/3x-2/x+y(x+y/3x-x-y)]/x-y/x 化简：{2/3x-2/(x+y)[(x+y)/3x-x-y]}/(x+y)/x 计算2/3x-2/x+y(x+y/3x-x-y)/x-y/x 化简3x-2/(x+y)[(x+y)/3x-x-y]÷(x-y)/x [(x-y)^2-(x+2y)(x-2y)]/y 计算[2x^2-(x+y)(x-y)][(-x-y)(y-x)+2y^2] (x+y)^2(x-y)^2-(x-y)(x+y)(x^2+y^2)分解因式 （x-y)(x-y)2(y-x) (x+2y-?）(x-2y+?)