Áp dụng BĐT \(\left|a\right|+\left|b\right|\ge\left|a+b\right|\) ta có:
\(A=\left|x-1,5\right|+\left|x-2,5\right|\)
\(=\left|x-1,5\right|+\left|2,5-x\right|\)
\(\ge\left|x-1,5+2,5-x\right|=1\)
Dấu "=" xảy ra khi \(1,5\le x\le2,5\)
Vậy \(Min_A=1\) khi \(1,5\le x\le2,5\)