Question

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

Answer 1

Hello,

$u_{1} =-5\\ u_{2} =-5+d\\ u_{3} =-5+2d\\ u_{4} =-5+3d\\ ...\\ u_{10} =-5+9d=13\\ ==\ \textgreater \ 9d=18 \\ ==\ \textgreater \ d=2$

Answer 2

Answer:

2

Step-by-step 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