Question 635935
This is a mixture of inequalities and absolute values. 
Solve the following absolute value in equalities: 
|x+1| is less than or equal to |x-3|
**
|x+1|≤|x-3|
solve for 2 conditions:
x+1≤x-3
1≤-3 (reject, not true)
..
x+1≤-x+3
2x≤2
x≤1
solution: (-∞,1]