Question

in an Ap,if the common difference (d)=-4,and the seventh term (a7)is 4,then find the first term

Answer 1

The first term is 28

Answer 2

if in AP,  if D=-4

and seventh term is 4  then we need to find a=?

according to question,
a+6d=4
a+6×-4=4
a+{-24}=4
a-24=4
a=4+24
a=28

hence the first term is 28