we have the ordered pairs
(1,-3)
(2,1)
(3,5)
(4,9)
the data set is equal to
-3,1,5,9,...
a1=-3 ---> first term
a2=1
a3=5
a4=9
Find out the difference between consecutive terms
a2-a1=1-(-3)=4
a3-a2=5-1=4
a4-a3=9-5=4
so
The common difference d=4
The equation is given by the formula
[tex]\begin{gathered} a_n=a_1+d(n-1) \\ a_n=-3+4(n-1) \end{gathered}[/tex]
The answer is the third option
