Question

A theater has 60 seats on the front row. There are seven additional seats in each following row.

Part A: Write a rule to represent the number of seats in any given row as an explicit formula
Part B: How many seats are in the 18th row?

Answer 1

(a) y(x)=53+7x

(b) 179

Explanation:

Since the first row has 60 seats and next row has 7 additional seats then we can represent it as

First row=60

Second row=60+7=67

Third row=67+7=74

The difference is always 7. If you deduct 7 from dirst row we get 60-7=53 seats

To get rhe number of seats in any row x then let y be the number of seats in row x

y=53+7(x)

For raw 1

Y=53+7(1)=60

For raw 2

Y=53+7(2)=67

Therefore, the formula for number of seats at any row will be

y(x)=53+7(x)

(b)

Using the above formula

y(x)=53+7(x)

Replace x with 18 hence

Y(18)=53+7*(18)=179 seats