This shows that Billy will have $12, 168.25 after 12 years
<h3>Compound interest</h3>
The formula for calculating the compound interest is expressed as:
From the information given, the amount is expressed as;

This shows that Billy will have $12, 168.25 after 12 years
Learn more on compound interest here: brainly.com/question/24924853
The average rate of change for this is the slope of the secant line that connects those 2 points (3, y) and (15, y). What we need for the slope formula of change in y over change in x are the y values which are unknown as of right now. We can find them though! Don't worry! The equation is y = .01(2)^x. Using that equation, let's sub in both the 3 and the 15 and find the corresponding y values. Subbing in first a 3 gives you y = .01(2)^3, and y = .08. Subbing in a 15 gives you y = .01(2)^15 and y = 327.68. Now we have the coordinates we need to find the slope of the secant line connecting those 2 points: (3, .08) and (15, 327.6). Fitting those into the slope formula gives us (327.68-.08)/(15-3). Simplifying that is 327.6/12 which divides out to 27.3
One way in which to do this problem would involve subtracting 5 from 7 (result: 2) and then subtracting 3/5 from 8/9.
To subtract 3/5 from 8/9, you'd need to find the lowest common denominator (LCD) of 3/5 and 8/9, convert both fractions to have this LCD, and then subtract.
The LCD is (5)(9)=45. Then 8/9 and 3/5 become 40/45 and 27/45.
Subtracting 27/45 from 40/45 results in the fraction 13/45.
Then the full solution is 2 13/45.
You could also do this problem by converting 7 8/9 and 5 3/5 into improper fractions:
71/9 - 28/5. Again, the LCD is 45. Can you rewrite both fractions with 45 as the common denominator and then perform the subtraction?