Question

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

Answer 1

a+6d =4
a+6*(-4)=4
a-24=4
a=28

Answer 2

If d=-4
and a7=4
then
a+6d=4
a+6×-4=4
a-24=4
a=4+24
a=28