\(\frac{3-x}{5}=\frac{1}{4}\)
\(\Rightarrow\left(3-x\right)\cdot4=5\cdot1\)
\(\Rightarrow12-4x=5\)
\(\Rightarrow4x=12-5\)
\(\Rightarrow4x=7\)
\(\Rightarrow x=7:4\)
\(\Rightarrow x=\frac{7}{4}\)
Vậy \(x=\frac{7}{4}\)
\(3-\frac{x}{5}=\frac{1}{4}\)
\(\Leftrightarrow\frac{x}{5}=3-\frac{1}{4}\)
\(\Leftrightarrow\frac{x}{5}=\frac{11}{4}\)
\(\Leftrightarrow4x=5.11\)
\(\Leftrightarrow4x=55\)
\(\Leftrightarrow x=55:4\)
\(\Leftrightarrow x=\frac{55}{4}\)
\(\frac{3-x}{5}=\frac{1}{4}\)
=> 4(3-x) = 1.5
=> 12 - 4x = 5
=> 12 - 5 = -4x
=> 7 = -4x
=> x = 7/-4
