Question

初一数学分式加减

x+y/(x-y)(y-z) + x+z/(y-x)(y-z)

a- 4/2-a + 2

(x+2/x^2-2x - x-1/x^2-4x+4)·x/x-4
（要过程）

Answer 1

1.= {x+y-(x+z)}/(x-y)(y-z)=1/(x-y)

2.=0

3.=(4-6x+1/x^2)-4=1/x^2-6x

Answer 2

(1)=x+y/(x-y)(y-z) - x+z/(x-y)(y-z)
={x+y-(x+z)}/(x-y)(y-z)
=y-z/(x-y)(y-z)
=1/x-y
(2)=a+2- 4/2-a
=(4-a^2-4)/2-a
=a^2/a-2
(3)={x+2/x(x-2) - x-1/(x-2)^2}*x/x-4
={(x+2)(x-2)-x(x-1)}/x(x-2)^2 *x(x-4)
=1/(x-2)^2