\[4 - 2,5x\]
\[x = 6:\]
\[4 - 2,5 \cdot 6 = 4 - 15 = - 11.\]
\[x = - 3:\]
\[4 - 2,5 \cdot ( - 3) = 4 + 7,5 = 11,5.\]
\[x = - \frac{2}{3}:\]
\[4 - 2,5 \cdot \left( - \frac{2}{3} \right) = 4 + \frac{25}{10} \cdot \frac{2}{3} =\]
\[= 4 + \frac{25 \cdot 2}{10 \cdot 3} = 4^{\backslash 3} + \frac{5}{3} =\]
\[= \frac{12}{3} + \frac{5}{3} = \frac{17}{3} = 5\frac{2}{3}.\]
\[x = 0,7:\]
\[4 - 2,5 \cdot 0,7 = 4 - 1,75 = 2,25.\]