Question

S=17+20+23+26+...+464

Answer 1

aflăm cate nr sunt:(464-17):3+1=447:3+1=149+1=150
s=(464+17)*150:2=481*75=36075

Answer 2

$17=14+3$
$20=14+6=14+3*2$
$23=14+9=14+3*3$
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$464=14+150=14+3*150[<span>/tex</span>] Daca adunam toate numerele [tex]S=17+20+23+..+464=14+3*1+14+3*2+14+3*3+...+14+3*150=14*150+3(1+2+3+..+n)=14*150+3*\frac{150*151}{2}=2100+33975=36075$