1. combine like terms (2x and -7x) to create -5x
2. subtract 5 from each side to create: -5x=10
3. divide both sides by -5
4. x=-2
This is a compound interest problem, therefore s(t) should be in the form:

where:
t = time in years
s(t) = the value of your item after t years
a = the initial value of your item
r = rate
Therefore, we already know that a = 245$.
Now, we can calculate r:

![r = \sqrt[t]{ \frac{s}{a} }](https://tex.z-dn.net/?f=r%20%3D%20%20%5Csqrt%5Bt%5D%7B%20%5Cfrac%7Bs%7D%7Ba%7D%20%7D%20)
![r = \sqrt[5]{ \frac{560.50}{245} }](https://tex.z-dn.net/?f=r%20%3D%20%5Csqrt%5B5%5D%7B%20%5Cfrac%7B560.50%7D%7B245%7D%20%7D%20)
= 1.18
Therefore, the correct answers are
a = 245 and
r = 1.18
3217 + 13.1 + 1.3 can also be written as
3217.0
+ 13.1
1.3
----------
<span>3231.4
</span>
Your final answer should be <span>3231.4 or option 4. Hope this helps!</span>