2^n -1-2-2^2-2^3-........-2^100=1 mik cần gấp.giúp mik với
2 câu trả lời
2n−1−2−22−23−...−2100=1
⇒2n−(1+2+22+..+2100)=1
A=1+2+22+..+2100
2A=2+22+23+...+2101
2A−A=(2+22+23+...+2101)−(1+2+22+..+2100)
A=2101−1
⇒2n−(1+2+22+..+2100)=1=2n−(2101−1)
2n=2101−1+1=2101⇒n=101
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101$