Question

URGENT!!
Imi explica si mie cineva suma gauss ? + ex astea
(1+2+3+....+2018):2019

2x(1+2+3+....+2019):2020

URGENT

Answer 1

( 1 + 2 + 3 + ..... + 2018 ) : 2019 = 1009

= [ 2018 termeni × ( 1 + 2018 ) : 2} : 2019 =

= 1009 × 2019 : 2019 =

= 1 009

______________________________

2 × ( 1 + 2 + 3 + ...... + 2019 ) : 2020 = 2019

= [ 2 × 2019 × ( 1 + 2019 ) : 2 ] : 2020 =

= 2019 × 2020 : 2020 =

= 2019

__________________________

1 + 2 + 3 + ... + 2018  → aplic formula sumei lui Gauss = n ( n + 1 ) : 2

= 2018 termeni × ( 1 + 2018 ) : 2

                                 ↓

                         suma dintre primul si ultimul termen