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.
Answer:
1. a. His new texting speed after one month is 2 + 1/2 = 2.5 characters per second.
b. After two months it will be 2 + (1/2) * 2 = 3 characters / second.
c. Answer is 2 + 1/2 * 3 = 3.5 characters/second/.
2. The answer is s = 1/2m + 2
3. To solve for m we write 8 = 1/2m + 2 → 6 = 1/2m → m = 12 months.
4. 10r + 4 = 8 → 10r = 4 → r = 0.4
5. The variable r represents the rate she must increase her texting speed by per month.
6. A scenario could be "Allison has 37 marbles in a jar. She took out 5 from the jar and wants to divide the remaining amount equally among her 8 friends. How many marbles does each friend get?".
I divided the whole number by 2 and that was 1445 and then divided 1445 by 2.50 which was 578 and did the same thing except divided by 7.50 so its 578 kids and 192 adults
if you are looking for the solution then is <em>Infinitely many solutions</em>