Question

NEED HELP FAST WILL GIVE BRAINLIEST

Answer 1

In a music stadium, 35th row has 120 seats

and explicit formula is $a_{n}=3n+15$ is explicit formula for given sequence.

Step-by-step explanation:

In music stadium, there are 18 seats in first row and 21 seats in second row and it is continuously increasing by 3

Here, Arithmetic sequence is 18,21,24,27.....120

There Arithmetic sequence is given as a,a+d,a+d......a+(n-1)d

Where, a = First term = 18 and d = Increment = 3

Q (a) Write an explicit rule to model the sequence formed by the number of seats in each row.

Now, Create an explicit formula

$a_{n}=a+(n-1)d$

$a_{n}=18+(n-1)(3)$

$a_{n}=18+(3n-3)$

$a_{n}=3n+15$ is explicit formula for given sequence.

Q (b) Use the rule to determine which row has 120 seats.

Given $a_{n}=120$

To determine which row has 120 seats.

$a_{n}=3n+15$

$120=3n+15$

$105=3n$

$n=35$

Therefore, 35th row has 120 seats