Question

Denise is designing the seating arrangement for a concert an outdoor theater. To give everyone a good view, each row must have 6 more seats than the row before it, and the 1st row can only have 11 seats. Help Denise plan the rest of the seating by solving for how many seats are in row 18. Then explain to Denise how to create an equation to predict the number of seats in any row. Show your work, and use complete sentences.

Answer 1

Given:
1st term = 11
common difference = 6

f(x) = 11 + 6(x - 1)
f(18) = 11 + 6(18-1)
f(18) = 11 + 6(17)
f(18) = 11 + 102
f(18) = 113 number of seats in row 18.

Row
1              11    11  
2       11     6    17
3       17     6    23
4       23     6    29
5       29     6    35
6       35     6    41
7       41     6    47
8       47     6    53
9       53     6    59
10     59     6    65
11     65     6     71
12     71     6     77
13     77     6     83
14     83     6     89
15     89     6     95
16     95     6    101
17   101     6    107
18   107     6    113