Pojalusta pomogiteeeere srocno

a₁=100 d=1 [latex] a_{n}=999 a_{n}= a_{1}+d*(n-1) 999=100+1*(n-1) 899=n-1 n=900 [/latex] [latex] S_{n} = \frac{2 a_{1}+d*(n-1) }{2}*n [/latex] [latex] S_{900} = \frac{2*100+1*(900-1)}{2}*900= \frac{200+899}{2}*900=494550 [/latex]