# How do you find the term n=13, given a_1=-5 and d=7?

Feb 22, 2017

${a}_{13} = 79$

#### Explanation:

For an $\textcolor{b l u e}{\text{arithmetic sequence}}$ the nth term is found by using the nth term formula.

$\textcolor{\mathmr{and} a n \ge}{\text{Reminder }} \textcolor{red}{\overline{\underline{| \textcolor{w h i t e}{\frac{2}{2}} \textcolor{b l a c k}{{a}_{n} = {a}_{1} + \left(n - 1\right) d} \textcolor{w h i t e}{\frac{2}{2}} |}}}$

$\Rightarrow {a}_{13} = - 5 + \left(12 \times 7\right)$

$\textcolor{w h i t e}{\Rightarrow {a}_{13}} = - 5 + 84$

$\textcolor{w h i t e}{\Rightarrow {a}_{13}} = 79$