Question

Pojalusta pomogiteeeere srocno

Answer 1

a₁=100
d=1
$a_{n}=999 a_{n}= a_{1}+d*(n-1) 999=100+1*(n-1) 899=n-1 n=900$

$S_{n} = frac{2 a_{1}+d*(n-1) }{2}*n$
$S_{900} = frac{2*100+1*(900-1)}{2}*900= frac{200+899}{2}*900=494550$

Answer 2

Задание