Find the indicated term for the given arithmetic sequence Th

Find the indicated term for the given arithmetic sequence. The 80th term of -2,-9, -16,... 80

-1 , -9 , -16 ....

first term = -2

common difference = next term - previous term = -9 - (-2) = -7
nth term of arithmetic sequence is given by

an = a1 + (n-1)*d

where , a1 = first term

d = common difference

a80 = -2 + ( 80 - 1) * -7

a80 = -2 - 553 = -555

a80 = -555