Answer:
5.5%
Step-by-step explanation:
To solve this problem we can use a modified version of the simple interest formula which is shown below:

<em>I = interest amount</em>
<em>P = principal amount</em>
<em>t = time (years)</em>
<em />
The first step is to find the interest gained from the investment.

Next, plug in the values into the equation:
Multiply the bottom values
Divide the values

The last step is to convert 0.055 into a percent:

The interest rate is 5.5%
3x+4=x+2
2x+4=2
2x=-2
-2/2
X=-1
Y=-1+2
Y= 1
Solution= (-1,1)
You would need 13 cases. If you would like an explanation of my answer, let me know.