Question

Find the 12th term of the sequence -15,-9,-3, 3

Answer 1

first term (a) = -15
common difference(d)= -9-(-15)
= -9+15=6
So,
12th term(a12)= a +(n-1)d
= -15+(12-1)×6
= -15 + 11×6
= -15+66
= 51