Question

sa se calculeze 1+3+5.....19 formula lui gauss​

Answer 1

Răspuns:

Explicație pas cu pas:

1 + 3 + 5 + ...... + 19 =

-> ( 19 - 1 ) : 2 + 1 = 10 termeni are suma

= 10 × ( 1 + 19 ) : 2 =

= 10 × 20 : 2 =

= 200 : 2 =

= 100

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Sau:

S = 1 + 3 + 5 + ....... + 19

S =19 +17+15 + ..... + 1

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2 × S = 20 + 20 + 20 + .... + 20

2 × S = 20 × 10

2 × S = 200

S = 200 : 2

S = 100