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aratati a numarul b=1+3+5+...+2017 este patrat perfect

ajutati ma va rog e urgent


Răspuns :

Răspuns:

Explicație pas cu pas:

b = 1 + 3 + 5 + ..... + 2017

( 2017 - 1 ) : 2 + 1 = 2016 : 2 + 1 = 1008 + 1 = 1009 termeni are suma cu ratia 2

b = 1009 × ( 1 + 2017 ) : 2

b = 1009 × 2018 : 2

b = 1009 × 1009

b = 1009²  → patrat perfect

1+3+5+...+2017=

=1+2+3+4+5+6+...+2016+2017-(2+4+6+...+2016)=

=2017×2018:2-2(1+2+3+...+1008)=

=2017×1009-2×1008×1009:2=

=2017×1009-1008×1009=

=1009×(2017-1008)=

=1009×1009=

=1009²