Question

Consider the sequence of numbers 50, 48, 46, 44, using n to represent a position of a number in this sequence, write an expression that allows you to calculate the nth number

Answer 1

The given sequence is

$50,48,46,44,....$

Here the first term, a is 50.

And the difference between two consecutive terms are

$48-50=46-48=44-46=-2$

So the difference is constant, which is -2. Therefore the sequence is arithmetic .

And the nth term of aritmnetic series is given by

$a_{n} = a+(n-1)d$

Substituting the values of a and d, we will get

$a_{n} = 50+(n-1)(-2) \\ a_{n} = 50 -2n+2 \\ a_{n} = 52-2n$