Question

Is 9,7,5,3,1 , -1 , -3, an Arthemeric progression why??

Answer 1

Answer:

$\large\mathrm\red{Yes , it's \: an \: AP}$

Because, in this sequence of numbers, The common difference is constant.

Answer 2

$a_2-a_1=a_3-a_2=a_4-a_3,.. ..=d$

$7-9=(-2)\\5-7=(-2)\\3-5=(-2)\\1-3=(-2)\\(-1)-1=(-2)\\(-3)+1=(-2)$

every terms are having the same difference that is -2 so they are in AP