Find the first term and common difference of the Arithmetic Progressions whose nth terms are given below (ii) tn = 4 - 7n

Find the first term and common difference of the Arithmetic Progressions whose nth terms are given below

(ii) tn = 4 - 7n

Solution :

To find the 1st term of the sequence, we have to apply n = 1.

1st term  t1 =  4 - 7(1)  t1 = 4 - 7  = -3

2nd term  t2 =  4 - 7(2)  t2 = 4 - 14  = -10

d = t2 -  t1   = -10 - (-3)  = -10 + 3 ==> d  = -7

Hence the first term and common difference are -3 and -7 respectively.