Question

Tìm 3 số nguyên dương a,b,c thỏa mãn : \(a\le b\le c\); \(\left(1+\frac{1}{a}\right)\left(1+\frac{1}{b}\right)\left(1+\frac{1}{c}\right)=3\)

Answer 1

mày ghi de sai

phai lon hon 3

Answer 2

Vì \(a\le b\le c=>\frac{1}{a}\ge\frac{1}{b}\ge\frac{1}{c}=>1+\frac{1}{a}\ge1+\frac{1}{b}\ge1+\frac{1}{c}\)

\(=>\left(1+\frac{1}{a}\right)\left(1+\frac{1}{b}\right)\left(1+\frac{1}{c}\right)\ge3\left(1+\frac{1}{c}\right)\)

\(=>3\left(1+\frac{1}{c}\right)\le3=>1+\frac{1}{c}\le1=>\frac{1}{c}\le0=>1\le0\)

Đề sai thì phải bn à