The number of seats in each row of a theater forms an arithmetic sequence. the fifth row contains 22 seats. the tenth row contains 37 seats . how many seats are in the first row?

Let denote the number of seats in the -th row. is arithmetic, so

for some constant .

We're told and , so that

and so on up to

The pattern continues:

and so on up to

$12. that is my answer.

d. corresponding side lengths in similar triangles are proportional in length.

step-by-step explanation: