Question

dau coroana.8 prin suma Gauss și​

Answer 1

Răspuns:

a)

1 + 2 + ............+ 50

S =( 1 + 50 ) • 50 supra 2

S = 51 • 50 supra 2

S = 2550 supra 2

S = 1275

1 + 2 + 3 + ....... + 200

S = ( 1 + 200 ) • 200 supra 2

S = 201 • 200 supra 2

S = 40200 supra 2

S = 20100

1275 + 20100 = 21375

b) 31 + 32 + 33 +........+ 100

S = (31+1)+(30+2)+(30+3)+.........(30+70)

S = 30•70 + ( 1 + 2 + 3 + ........+ 70 )

S = 2100 + 71 • 70 : 2

S = 2100 + 4970 : 2

S = 2100 + 2485

S = 4585

c) 2 + 4 + 6 +.........+ 100

S= 2•1 + 2•2+2•3+.........2•50

S= 2•( 1 + 2 + 3 +......... + 50 )

S = 2• 51 • 50 : 2

S = 102 • 50 : 2

S = 5100 : 2

S = 2550

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