You can add a lot of numbers (or so I think). One number I think you can add is 31.
Answer:
The integer is -16
Step-by-step explanation:
The first scuba diver is 23 feet below sea level. THe second is 7 feet closer.
23 - 7 = 16. He is still under sea level, so it would be -16
4.07 * 100 = 407%
407 / 100 = 4.07
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.