Question

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

Answer 1

2

Explanation:

equation: f(n) = a + (n - 1)d

substitute: 13 = -5 + (10 - 1)d

solve: 13 = -5 + 9d

+5 +5

18 = 9d

9 9

d = 2

Answer 2

Hello,


`u_(1) =-5\\ u_(2) =-5+d\\ u_(3) =-5+2d\\ u_(4) =-5+3d\\ ...\\ u_(10) =-5+9d=13\\ ==\ \textgreater \ 9d=18 \\ ==\ \textgreater \ d=2`