1/x(x+1)+1/(x+1)(x+2)+…+1/（x+4)(x+5) 求 ①（x-1/y)÷（y-1/x) ②约分

1、x(x-y)(x+y)-x(x+y)^2 约分下列分式(x-y)/(y-x)³(x²-9)/(6-2x)(x²-1)/(x-x
分式的通分与约分①：x/a(x-y),y/b(y-x)；②：1/x^2-1,2x/x^2-3x+2； (1)(x^2/x)-y-x-y 求y=(5x-1)/(4x+2) (x 求函数y=\x-1\+\x-2\+\x-3\+\x-4\+\x-5\+\x-6\+.+\x-10\的最小值 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-( 已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y 把分式xy-y/x-2x+1约分 y=(x^2+x)/(x+1) 已知4x=9y求(1)x+y/y (2)y-x/2x 1、X^2-4\X^2+5X-14 约分