Question

Va rog frumos am profesoral foarte stricta! ​

Answer 1

Răspuns:

Explicație pas cu pas:

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

3/4*7 =1/4 - 1/7

3/7*10 = 1/7 - 1/10

...............

3/61*64 = 1/61 - 1/64

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3/1*4 + 3/4*7 + 3/7*10 + .... + 3/61*64 = 1/1 - 1/4 + 1/4 - 1/7 + 1/7 - 1/10 + ... + 1/61 - 1/64 = 1/1 - 1/64 = 64/64 - 1/64 = 63/64

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

2/3*5 = 1/3 - 1/5

2/5*7 = 1/5 - 1/7

...............

2/61*63 = 1/61 - 1/63

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2/1*3 + 2/3*5 + 2/5*7 + ... + 2/61*63 = 1/1 - 1/3 + 1/3 - 1/5 + 1/5 - 1/7 + ... + 1/61 - 1/63 = 1/1 - 1/63 = 63/63 - 1/63 = 62/63

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63/64 - 62/63 = 63*63/64*63 - 62*64/63*64 = (3969 - 3968)/63*64

= 1/63*64

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128*126/63*64 = 4

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√4 = 2