Answer:
it is 6/7, you can simplify that fraction by dividing with 7
The x-intercepts are indeed -1 and 1.
The increasing intervals are listed as (-1, 0) u (1, infinity) not because -1 and 1 are not included points of the function, but because the function is not differentiable in those points, so you can't tell whether the function is increasing or decreasing there.
1. x = -4 ; f(x) = -(-4) = 4
2. x = -3 ; f(x) = 2(-3) + 1 = -5
3. x = 0 ; f(x) = 2(0) + 1 = 1
4. x = 2 ; f(x) = 2 + 3 = 5
5. x = 5 ; f(x) = 5 + 3 = 8
