# How do you find an equation that describes the sequence 3, 8, 13, 18,... and find the 70th term?

Mar 17, 2018

color (green)(70^(th) "term"  color(green)( a_70 = 348

#### Explanation:

${a}_{1} = 3$ First to find common difference $d$.

$d = {a}_{2} - {a}_{1} = {a}_{3} - {a}_{2} = {a}_{4} - {a}_{3} = 5$

${a}_{n} = {a}_{1} + \left(n - 1\right) \cdot d$

Therefore ${a}_{70} = {a}_{1} + \left(70 - 1\right) \cdot d = 3 + 69 \cdot 5 = 348$