Answer:
Penny would need to put in ~ $18,181.82
Step-by-step explanation:
Using the equation 
Where A = the total
P is equal to the starting amount
r is equal to the rate (percent)
and t is equal to the total time.
We can put in:
A = $40,000
r = 0.08 (8%)
t = 15

Round to the nearest whole cent
P = $18,181.82
Answer: -6 is your answer
This is just a simple division problem :)
5.262 ÷ 3 = 1.754
(Remember the bigger number always goes first when dividing)
Hope this helps
-AaronWiseIsBae
Just find the slope between the points
basically find (f(10)-f(7))/(10-7)
f(7)=7^2-3(7)-4=49-21-4=24
f(10)=10^2-3(10)-4=100-30-4=66
slope=(66-24)/(10-7)=42/3=14
average rate of change is 14
The answer is 9900000000 (thats 8 zeros) What you do is you find 10^10 which is 10000000000 (ten zeros) and multiply that by 7.92 to get 79200000000 then you just multiply it by 1/8 to get the answer.