Question

What is the 20th term of the arithmetic sequence 4, -2, -8, ... ?

Answer 1

`-110`

Explanation:

The standard `color(blue) " Arithmetic sequence "`

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

where a , is the first term , d , the common difference and the nth term is a + (n-1)d

here a = 4 , d = -4-2 = -8-(-2) = -6 and n = 20

`rArr " 20th term " = 4 + (19xx-6) = 4 -114 = -110`