Question

find the sum of first 100 terms of an ap whose nth term is 3-2n​

Answer 1

Answer:

series :

1,2,3,4........100

a=1 ,d=1

Step-by-step explanation:

$sn = \frac{n}{2} (2a + (n - 1)d$

$s100 = \frac{100}{2} (2(1) + (100 - 1)1$

$s100 = 50(2 + 99)$

$s100 = 50x101$

$s100 = 5050$

tn=a+(n-1)d

tn=1+(3-2n-1)

tn=1+2-2n

tn=3-2n