1 + 2/(x+1) - 2/x ≤ 0
[x(x+1) + 2x - 2(x+1)] / [x(x+1)] ≤ 0
(x2+x-2) / [x(x+1)] ≤ 0
[(x+2)(x-1)] / [x{x+1}] ≤ 0
Numerator = 0 when x = -2 and 1. Denominator = 0 when x = 0 and -1.
Set up the following collection of intervals ____-2_____-1____0_____1_______and choose a test point in each interval.
When x < -2, numerator and denominator are both positive. So, the expression is positive.
When -2<x<-1, numerator < 0 and denominator > 0. So, the expression is negative
When -1<x<0, numerator <0 and denominator < 0. So, the expression is positive
When 0<x<1, numerator < 0 and denominator > 0. So, the expression is negative,
When x > 1, the expression is positive
The expression = 0 when x = -2 and 1
The expression is undefined when x = 0 and x = -1
Solution set: [-2, -1)∪(0,1]