(X.100-0,7357):0,01-15,88=0,55

=>(X.100-0,7357):0,01=0,55+15,88

=>(X.100-0,7357):0,01=16,43

=>X.100-0,7357=16,43.0,01

=>X.100-0,7357=0,1643

=>X.100=0,1643+0,7357

=>X.100=0,9

=>X=0,9:100

=>X=9/1000=0,009

Ta có: \(\left(a+b+c\right)\left(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\right)\ge3\sqrt[3]{abc}.3\sqrt[3]{\frac{1}{abc}}=9\)

\(\Rightarrow\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\ge\frac{9}{a+b+c}=\frac{9}{3}=3\)

Dấu "=" xảy ra khi a = b = c = 4-1 = 3.

Mình biết nè !