The given A.P is -2, -4, -6, … -100
d = -4 – (-2) = -4 + 2 = – 2
Finding the 12 term from the last term
a = -100, d = 2 (taking from the last term)
n = 12
tn = a + (n – 1)d
t12 = – 100 + 11 (2)
= -100 + 22 = -78
∴ The 12th term of the A.P from the last term is – 78