An indoor auditorium has a small side section that models an arithmetic sequence where the third row has 5 seats and the tenth row has 26 seats. If that section has 14 rows, how many seats would be in the last row?
a+2d = 5
a+9d = 26
7d = 21, so d=3 and a = -1
A14 = -1+14*3 = 41