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 ...
f(n) = -n^2 -3n +5
Answer:
i wanna say yes it is a natural number, i hope this helps
We have for this case:
For each language we have:
Number of people who speak Spanish:
Spanish = 8 + 4 = 12
Number of people who speak Chinese:
Chinese = 5 + 6 = 11
Number of people who speak both languages:
Both = 3 + 2 = 5
Adding we have:
12 + 11 + 5 = 28
Answer:
28
option A
75 hundreds 0 tens(or skip) 2 ones
