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 $

step-by-step explanation:

the areas of two similar triangles are 18 cm2 and 8 cm2. one of the sides of the first triangle is 4.5 cm. what is the length of the corresponding side of the other triangle?