r****e 发帖数: 9 | 1 I met a problem which is easy intuitively, but I don't know how to prove it.
Please help me on this.
For all positive integer n, a, and b, if n|ab, gcd(a, n) = 1, then n|b.
gcd is greatest common divisor, n|ab means n divides a*b.
Thanks | B****n 发帖数: 11290 | 2 if (a,n)=1 then there exists integers x and y such that ax+ny=1
n|ab=>n|axb=>n|(1-ny)b=>n|b
【在 r****e 的大作中提到】 : I met a problem which is easy intuitively, but I don't know how to prove it. : Please help me on this. : For all positive integer n, a, and b, if n|ab, gcd(a, n) = 1, then n|b. : gcd is greatest common divisor, n|ab means n divides a*b. : Thanks
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