Đáp án:
Ta có :
`a/b=25/35=5/7`
`=>a=(5b)/7`
Mà `BCNNN(a,b).ƯCLN(a,b)=ab`
`=>4235=(5b)/7.b`
`=>4235=(5b^2)/7`
`=>5b^2=29645`
`=>b^2=5929`
`=>b=77`
`=> a=(5b)/7 <=> a=(5.77)/7=55`
`=>a=55 ; b=77`
`=> a/b = 55/77=5/7`
Giải thích các bước giải:
`a/b=25/35=5/7\toa=5/7 .b`
$BCNN(a,b)×ƯCLN(a,b)=4235`
`\to` tích `a.b=4235`
`\to5/7 .b×b=4235`
`\to5/7 .b²=4235`
`\to b²=5929`
`\to b=77`
`\to a=5/7 .77=55`
`\to a/b=5/7`
Vậy phân số cần tìm là `5/7`
Giúp mình bài này với ạ. Cảm ơn!!!
chỉ Cho mình với mai nộp bài rồi chỉ Cho mình với mai nộp bài rồi chỉ Cho mình với mai nộp bài rồi chỉ Cho mình với mai nộp bài rồi
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