Question

If 7 term of an AP is - 14 whose common difference is -2 then the first term a
A)-2
B) 2
C) 7
D) -7​

Answer 1

In the question :

• 7th term of AP = - 14
• Common difference ‘d’ = - 2

We shall have to find :

• First term = a

We know that :

• a + (n - 1) d = aₙ

Here :

• a = First term
• d = Common difference
• n = No. of the term
• aₙ = nth term of the AP

Substituting the values and solving :

• a + (7 - 1) (- 2) = - 14
• a + (6) (- 2) = - 14
• a - 12 = - 14
• a = - 14 + 12
• a = - 2

                                                                     

Therefore, the first term of an AP whose 7th term is - 14 and ‘d’ is - 2 is - 2 [0ptionA].