Răspuns:
Explicație pas cu pas:
1/1*2 = 1/1 - 1/2
1/2*3 = 1/2 - 1/3
.......
1/24*25 = 1/24 - 1/25
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1/1*2 + 1*2*3 + ... + 1/24*25 = 1/1 - 1/2 + 1/2 - 1/3 + ... + 1/24 - 1/25
= 1/1 - 1/25 = 25/25 - 1/25 = 24/25
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1/25*26 = 1/25 - 1/26
1/26*27 = 1/26 - 1/27
........
1/49*50 = 1/49 - 1/50
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1/25*26 + 1/26*27 + ... + 1/49*50 = 1/25 - 1/26 + 1/26 - 1/27 + ... + 1/49 - 1/50
= 1/25 - 1/50 = 2/50 - 1/50 = 1/50
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24/25 - 1/50 = 48/50 - 1/50 = 47/50
1/94*47/50 = 1/100
x = √1/100 = 1/10 ∈ R
