Question

What is the first term in the sequence for which d = -2 and a7 = 3?

A. -6
B. 12
C. 15
D. -12

Answer 1

First term is 15

Explanation:

Given data:

`a_(7) =3\\d=-2`

Now,

`a+6d=3.....(1)\\a_(n) =a+(n-1)d\\\\\\From equation (1)\\a+6(-2)=3\\a-12=3\\a=12+3\\a=15`

Therefore first term a =15

Correct option is (c)