Answer:
21
Step-by-step explanation:
put 21 were x is and then divide 21÷7=3
Answer:

We divide both sides by 100000 and we got:

Now we can apply natural logs on both sides;

And then the value of t would be:

And rounded to the nearest tenth would be 9.2 years.
Step-by-step explanation:
For this case since we know that the interest is compounded continuously, then we can use the following formula:

Where A is the future value, P the present value , r the rate of interest in fraction and t the number of years.
For this case we know that P = 100000 and r =0.12 we want to triplicate this amount and that means
and we want to find the value for t.

We divide both sides by 100000 and we got:

Now we can apply natural logs on both sides;

And then the value of t would be:

And rounded to the nearest tenth would be 9.2 years.
-2 !!!!!!!!!!!!!!!!!!!!!!!
The dots you see on step 1 and step 2 mean to multiply
when you divide a fraction you actually multiply it then whatever you get you simplify it. simple :) hope it helped