What is the nth term of the arithmetic sequence 121,99,77,55?

Apr 29, 2016

143 - 22n

Explanation:

For the standard Arithmetic sequence.

a,a+d,a+2d,a+3d,............. , a+(n-1)d

a is the first term ,d, the common difference and

$\textcolor{red}{| \overline{\underline{\textcolor{w h i t e}{\frac{a}{a}} \textcolor{b l a c k}{a + \left(n - 1\right) d} \text{ the nth term } \textcolor{w h i t e}{\frac{a}{a}} |}}}$

here a = 121 and d = 99-121 =77-99 = -22

hence nth term = 121 -22(n - 1) = 121 -22n + 22 = 143 - 22n