F(-10)=-2, f(-8)=5, and f is continuous. All these mean that f(x) is 0 for x in between -10 and -8.
That is, f at -10 is negative, then at -8 is positive. So the graph of f "cuts" the x-axis for an x value in (-10, -8).
Since there is only one value such that f(x)=0, x can only be -9.
Answer: -9
The answer is 2x
3
+5x
2
−x−6
4. First find how much sauce is used for 1 person:
2 ÷ 7 = 0.285714285714286
0.285714285714286cups of sauce will make spaghetti for one person.
0.285714285714286 • 210 = 60
60 cups of sauce for 210 people.
5. Found out how much he read in one minute:
40 ÷ 50 = 0.8
0.8 • 80 = 64
In 80 minutes, she will read 64 pages.
6. Found out how much he earns after one month:
9 ÷ 6 = 1.5
1.5 • 12 = 18
18 • 2 = 36
After two years, he will have 36 days of vacationing time
61.26 in^2
Explanation: plug in the formula to get SA=2π1.5^2+2π(1.5)(5)