Question

poate cnv pls pls psl​

Answer 1

Răspuns:

Explicație pas cu pas:

1/2*2/3*3/4*...*79/80*80/81*81/82 = 1/82

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1/1*2 = 1/1 - 1/2

1/2*3 = 1/2 - 1/3

1/3*4 = 1/3 - 1/4

........

1/81*82 = 1/81 - 1/82

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1/1*2 + 1/2*3 + 1/3*4 + ... + 1/81*82 = 1/1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 * ...+ 1/81 - 1//82 = 1/1 - 1/82 = 82/82 - 1/82 = 81/82

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1/82*81/82 = 81/82^2 = 9^2/82^2

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√9^2/82^2 = 9/82