Answer:
y=x+5
Step-by-step explanation:
The answer is C
Radius is 8.2 and circumference is 51.52
₇P₅ is a permutation. you can find this setting in the statistics menu of your scientific calculator (i think).
If you don't have a scientific calculator, you can use the following formula:
nPr = 
₇P₅ = 
= 
= 
= 7 * 6 * 5 * 4 * 3
= 2520
Answer: C