Andrea is designing the seating arrangement for a concert in her local park. to give everyone a good view, each row must have 4 more seats than the row before it, and the 1st row can only have 10 seats. andrea plan the rest of the seating by solving for how many seats are in row 20. then explain to andrea how to create an equation to predict the number of seats in any row. show your work, and use complete sentences.

This is an arithmetic sequence because each term has a common difference when compared to the previous term.

The rule for any arithmetic sequence is:

a(n)=a+d(n-1), a=initial term, d=common difference, n=term number.

In this case a=10 (first row) and d=4 (each row if 4 more than the prior one)

a(n)=10+4(n-1)

a(n)=10+4n-4

a(n)=4n+6  That is the rule to find the number of seats in any row.

and

a(20)=4(20)+6=86 seats in the 20th row.