Question

The first term of an arithmetic sequence is -5, and the tenth term is 13. Find the common difference.

8/9
1.8
2

Answer 1

The formula for the nth term of a arithmetic sequence is
\[a_n=a_1+d(n-1)\]
You have \[a_1=-5,~n=10,~a_{10}=13\]
Plug in to find d
\[13=-5+d(10-1)\]