Question

an A.P. , if the common difference (d) = -4 and the seventh term (a7) is 4 , then find the first term. *

Answer 1

Answer:

It is simple I will show you how it is,

a7= 4

d= -4

So we know the the equation:

An= a+ (n-1)d

4 = a+ (7-1) x -4

4 = a+ 6 x-4

4 =  a - 24

 a = -4+24

 a = 20

AP= 20, 16, 12, 8............

I hope this answer will help for more understanding