Question

Write the possible explicit formula for the following sequences:
-17, -22, -27, -32

Answer 1

It's an arithmetic sequence:


`a_1=-17;\ a_2=-22;\ a_3=-27;\ a_4=-32\\\\a_n=a_1+(n-1)d\\\\\\d=a_2-a_1=a_3-a_2=a_4-a_3\\\\d=-22-(-17)=-22+17=-5\\\\a_n=-17+(n-1)\cdot(-5)=-17-5n+5=-12-5n\\\\\boxed{a_n=-5n-12}`