A = `2^{60}`/`2^{30}` . 4
B = 1/2 + 1/`2^2` + 1/`2^3` + .. + 1/`2^{100}`
C = 34 . (-20) + (-34) . 60 + 34 . 5
A = `2^{60}`/`2^{30}` . 4 B = 1/2 + 1/`2^2` + 1/`2^3` + .. + 1/`2^{100}` C = 34 . (-20) + (-34) . 60 + 34 . 5
By Eden
By Eden
A = `2^{60}`/`2^{30}` . 4
B = 1/2 + 1/`2^2` + 1/`2^3` + .. + 1/`2^{100}`
C = 34 . (-20) + (-34) . 60 + 34 . 5
#KhanhHuyen2006 – Xin câu trả lời hay nhất
`A = 2^{60}/(2^{30} . 4)`
`-> A = 2^{60}/(2^{30} . 2^2)`
`-> A = 2^{60}/2^{32}`
`-> A = 2^{28}`
`B = 1/2 + 1/2^2 + 1/2^3 + … + 1/2^{100}`
`-> 2B = 1 + 1/2 + 1/2^2 +….+ 1/2^{99}`
`-> 2B – B = (1 + 1/2 + 1/2^2 +….+ 1/2^{99}) – (1/2 + 1/2^2 + 1/2^3 + … + 1/2^{100})`
`-> B = 1 – 1/2^{100}`
`-> B = 1`
`C = 34 . (-20) + (-34) . 60 + 34 . 5`
`-> C = 34 . (-20) + 34 . (-60) + 34 . 5`
`-> C = 34 . [-20 + (-60) + 5]`
`-> C = 34 . (-75)`
`-> C = -2550`
Đáp án:
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