form 2 math

1)
(x + 1) / (x - 1) + 1 / (1 - x)
= (x + 1) / (x - 1) - 1 / (x - 1)
= (x + 1 - 1) / (x - 1)
= x / ( x - 1)

2)
a + b = 2 / (1 - x) + 1 / (1 + x)
= [2(1 + x) + (1 - x)] / (1 - x)(1 + x)
= (3 + x) / (1 - x)(1 + x)

a - b = 2 / (1 - x) - 1 / (1 + x)
= [2(1 + x) - (1 - x)] / (1 - x)(1 + x)
= (1 + 3x) / (1 - x)(1 + x)

therfore (a + b) / (a - b)
= [(3 + x) / (1 - x)(1 + x)] / [(1 + 3x) / (1 - x)(1 + x)]
=(3 + x) / (1 + 3x)

1) x+2
-----
x+1


2. sorry I am not sure how to solve.