BCNN(a;b)=72 thì 72=a.n=b.m \(\Rightarrow\)a=72:n và b=72:m và BCNN(n;m)=1

Mặc khác a+b=42 nên 42=\(\frac{72}{n}\)+\(\frac{72}{m}\)\(\Rightarrow\)\(42=\frac{72\left(n+m\right)}{n.m}\)\(\Rightarrow\)\(\frac{7}{12}\)=\(\frac{n+m}{n.m}\)=\(\frac{4+3}{4.3}\)

Vì n;m là nguyên tố cùng nhau và do a<b nên m<n. Ta chọn n=4 và m=3

- Khi n=4 và n=3 thì a=72:4=18 và b=72:3=24

Vậy (a;b)=(18;24)

I don't no

i don;t no ooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo love ò irisooooooooooooooooooooooooooooooooooooooooooooooooooooo

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dell có ai trả lời à

Đáp án là 18;24

thế mới đau