Just took the test. A is the right answer.
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:

Step-by-step explanation:






Answer:
The first, third and last one are true
Answer:
<h2>
Q 11. A and E</h2><h2>
Q 12. A</h2><h2>
Q 13. 4/3 cups of sugar</h2>
Step-by-step explanation:
The points (1, 3) and (15, 45) are proportional to point (3, 9) since they correspond with each other so if you multiply the point (1, 3) by a factor of 3, it would be (3, 9). If you divided the point (15, 45) by a factor of 5, it would be (3, 9).
In this equation, 2.95 represents the price of the gallons since it is being multipied by g, or the number of gallons.
If you were to multiply 2/3 cup of sugar and 1/2 cup of flour by 2, I would get 4/3 cups of sugar and 1 cup of flour. Why did I do this? Well, she uses 1 cup of flour so you can divded 1 by 1/2 is which 2.
Hope this helps, you can ask me why certain choices were not correct if you'd like.