Let n be the total number of puffs. Now we can write:

Adding the fractional value of n, we get:

Simplifying and rearranging gives us:

Therefore we can simplify to get:

and finally

The fraction of the puff that are tuna is found from:
Answer:
2 ≤ x < 7
Step-by-step explanation:
-1 ≤ x – 3 < 4
Add 3 to each side
-1+3 ≤ x – 3+3 < 4+3
2 ≤ x < 7
This problem can be solve by graphing (technology), as suggested.
The answer is posted as an attached image. We see that after about 14.75 years, the invading species will surpass the indigenous population.
If it needs to be solved mathematically and accurately, the math is a little more advanced, using the bisection method, or Newton's method.
However, we can also do that by trial and error, starting from 14.75. It is easier than you might think.
Post if you would like to have more information on one or the other methods.
Note: the scale of y has been shrunk by 1000, so each unit on the y-axis represents 1000 frogs.
Answer:
$7.22 or $7.217
Step-by-step explanation:
$7.22 would be the answer because 70% of 10.31 is what you are looking for which is 7.217 which is rounded to 7.22