the 8th of a linear sequence is 18 and the 12 term is 26 find the first term of the common difference and 20th term

2 answers

since the two given terms are four apart, d = (26-18)/4 = 2
so now you know that
a = 18 - 7*2 = 4
and a_20 = a+19d = _____
55 durbah ground