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.

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