4 people email 3 more people each so 12 people are emailed, then these 12 people email 3 more people each, so 36 people are emailed.
Answer: none
Step-by-step explanation: there are no WHOLE numbers between 39
In the default window of a graphing calculator, there is only one intersection that you see.
However, if you zoom out, you will see that they are 3 intersections to the pair of equations.