Đơn giản!
\(\left(0,825-\frac{x}{5}\right)\times3,6-0,72\times3=0,72\)
\(\Leftrightarrow\left(0,825-\frac{x}{5}\right)\times3,6-2,16=0,72\)
\(\Leftrightarrow\left(0,825-\frac{x}{5}\right)\times3,6=0,72+2,16\)
\(\Leftrightarrow\left(0,825-\frac{x}{5}\right)\times3,6=2,88\)
\(\Leftrightarrow0,825-\frac{x}{5}=2,88:3,6\)
\(\Leftrightarrow0,825-\frac{x}{5}=0,8\)
\(\Leftrightarrow\frac{x}{5}=0,825-0,8\)
\(\Leftrightarrow\frac{x}{5}=0,025\)
Vì \(\frac{x}{5}=x:5\Leftrightarrow x:5=0,025\)
\(\Leftrightarrow x=0,025\times5\)
\(\Leftrightarrow x=0,125\)
Vậy \(x=0,125\)
nguyễn thái thịnh bạn sai rồi
