C (n) = 500 + 4n ,

C is cost in dollars. of renting hall 4 prom given my equation:

C (n) = 500 + 4 n

n = # of students going to prom.

Calculate cost of renting hall
if 70 students go.

A. $108
B. $500
C. $780
D. $970

500 + 4(70)

500 + 280 = ?

So it would be $780. Thanks helper =)

correct, you're welcome

c=500+ 40n

To calculate the cost of renting the hall if 70 students go to the prom, we can plug in the value of n = 70 into the equation C(n) = 500 + 4n.

C(70) = 500 + 4*70
= 500 + 280
= 780

Therefore, the cost of renting the hall when 70 students go will be $780.

So, the correct answer is C. $780.