Question

in an AP, the common difference is 9 airst termnd seventh term is 4 , then find first term

Answer 1

let a be the 1st term
7th term =a +(7-1)d
4 = a + 6×9
4=a+54
4-54=a
-50 =a (i.e. first term)

Answer 2

D = 9
A7 = 4
ie , A + 6D=4
A+ 6x9= 4
A= 4 -54 = -50

A= -50

Hope this helps!!