Answer:
Compound interest is the addition of interest to the principal sum of a loan or deposit, or in other words, interest on interest. It is the result of reinvesting interest, rather than paying it out, so that interest in the next period is then earned on the principal sum plus previously accumulated interest.
Answer:

Step-by-step explanation:
The question is to simplify the expression 
First, we can eliminate the 2nd parenthesis expression by changing signs of all the terms since there is a "-" sign in front. Then we add the "Like Terms". The process is shown below:

The first answer choices (has some typos) is correct. The correct answer is 
<span>Simplifying
2x + -1y = 9
Solving
2x + -1y = 9
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add 'y' to each side of the equation.
2x + -1y + y = 9 + y
Combine like terms: -1y + y = 0
2x + 0 = 9 + y
2x = 9 + y
Divide each side by '2'.
x = 4.5 + 0.5y
Simplifying
x = 4.5 + 0.5y
Hope this helps :)
~I tried to space it out so it wont look like a bunch of mess scrambled up xD~</span>
If you have $8 and something’s cost $3 you will be getting $5 dollars back
Answer: C.) a and d
Step-by-step explanation: