ANSWER
The radius is 4
EXPLANATION
The given equation is:

We complete the square to get the expression in standard form:


We factor using perfect squares to get:

This implies that,

Comparing to

The radius is r=4
On Call's unit rate is about $2.86 per hour, since $10/3.5 hours= $2.86/1 hour
Talk Time's unit rate is about $2.50 per hour, since $1.25/0.5 hours= $2.50/1 hour
Since we are finding the unit rate of the cost per comic, we will need to divide $5 by 20 comics which you will get 0.25 cents and divide $7.50 by 30 comics which you will also get 0.25 cents.Therefore, the unit rate and constant of proportionality is 0.25 cents.
Since each table had 7 women and 3 men at each table, that would mean each table has 10 people. Since there are 9 tables he was waiting on, and 10 people at each table, multiply 9 x 10, and you will find that he served 90 people in total.
Answer:
its octagon. first and last one it has total 8 sides