2 * 6^(n-1)
a(sub4) = 2 * 6^(4-1)
a(sub4) = 2 * 6^3
a(sub4) = 2 * 216
a(sub4) = 432

This is equal to:

When you add a negative number, it turns into subtraction.
First, I would change it to mixed numbers:

Now, you need to change the denominators to make sure they are the same on both fractions. I changed the first fraction's denominator to 4 so they match. You can do this by multiplying the numerator by 2:

Now, you simply subtract:
10-9=1
1/4 is your answer.
I hope this helps :)
So,

1. Graph each inequality separately.
2. Choose a test point to determine which side of the line needs to be shaded.
3. The solution to the system will be the area where the shadings from each inequality overlap one another (purple area)
As for the system of inequalities we say it's unbounded.