1: there are 11 rows of seats in a concert hall: 15 seats are in the 1st row, 18 seats in the 2nd row, 21 seats in the 3rd row, and so on. what's the explicit equation and the recursive equation?

2: if the price per ticket is 27$, how much will be the total sales for a one-night concert if all the seats are taken?

Step-by-step explanation:

c.d.=21-18=18-15=3

y=15+3(x-1),x∈N,x≤18

recursive equation

a_{n}=a_{n-1}+3

2.

S_{18}=18/2{2×15+(18-1)×3}=9(30+51)=9×81=729

Total sales=729×27=19,683 $

the entire expression should be subtracted from 30. to subtract the quantity, distribute the negative sign, which changes the signs on the terms. so, the –2 changes to positive and gets added to 30 instead of subtracted from it.

hope this ! ^w^

nothjing

step-by-step explanation: