Answer:
f(n) = -n^2 -3n +5
Step-by-step explanation:
Suppose the formula is ...
f(n) = an^2 +bn +c
Then we have ...
f(1) = 1 = a(1^2) +b(1) +c
f(2) = -5 = a(2^2) +b(2) +c
f(3) = -13 = a(3^2) +b(3) +c
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Here's a way to solve these equations.
Subtract the first equation from the second:
-6 = 3a +b . . . . . 4th equation
Subtract the second equation from the third:
-8 = 5a +b . . . . . 5th equation
Subtract the fourth equation from the fifth:
-2 = 2a
a = -1
Then substituting into the 4th equation to find b, we have ...
-6 = 3(-1) +b
-3 = b
and ...
1 = -1 +(-3) +c . . . . . substituting "a" and "b" into the first equation
5 = c
The formula is ...
Set up two equations:
1st: P (for Price family) + J (for Jenkins family) = 45 hours
2nd: 20P + 35J = 1200 liters
Rewrite the first equation as P = 45 – J
Replace P in the second equation:
20(45-J) + 35J = 1200
Simplify:
900 -20J + 35J = 1200
900 +15J = 1200
Subtract 900 from both sides:
15J = 300
Divide both sides by 15:
J = 300/15
J = 20
Jenkins used theirs for 20 hours
Price used theirs for 45-20 = 25 hours.
242
Simplify the following:
11 ((9^2 - 5^2)/2^2 + 8)
Hint: | Evaluate 2^2.
2^2 = 4:
11 ((9^2 - 5^2)/4 + 8)
Hint: | Evaluate 5^2.
5^2 = 25:
11 ((9^2 - 25)/4 + 8)
Hint: | Evaluate 9^2.
9^2 = 81:
11 ((81 - 25)/4 + 8)
Hint: | Subtract 25 from 81.
| 7 | 11
| 8 | 1
- | 2 | 5
| 5 | 6:
11 (56/4 + 8)
Hint: | Reduce 56/4 to lowest terms. Start by finding the GCD of 56 and 4.
The gcd of 56 and 4 is 4, so 56/4 = (4×14)/(4×1) = 4/4×14 = 14:
11 (14 + 8)
Hint: | Evaluate 14 + 8 using long addition.
| 1 |
| 1 | 4
+ | | 8
| 2 | 2:
11×22
Hint: | Multiply 11 and 22 together.
| 2 | 2
× | 1 | 1
2 | 2 | 0
2 | 4 | 2:
Answer: 242
10 32 -9
10 -13 18
-9 -8 11
hope this helps
Answer: 102,400,000,000,000,000,000
First do 20^10 = 10,240,000,000,000.
Then, multiply 10,240,000,000,000 * 10,000,000 to get 102,400,000,000,000,000,000.
<em>Hope it helps <3</em>
