4. Реши уравнения: 1) 0,9x = 4,23; 2) 16x = 4; 3) 0,6x - 0,68 = 1.

Пошаговое решение:

• 1) \( 0.9x = 4.23 \)
  \( x = 4.23 / 0.9 \)
  \( x = 42.3 / 9 \)
  \( \begin{array}{c|cc cc} \multicolumn{2}{r}{4.7} \\ \cline{2-3} 9 & 42.3 \\ \multicolumn{2}{r}{36} \\ \cline{2-2} \multicolumn{2}{r}{63} \\ \multicolumn{2}{r}{63} \\ \cline{3-3} \multicolumn{2}{r}{0} \end{array} \)
  \( x = 4.7 \)
• 2) \( 16x = 4 \)
  \( x = 4 / 16 \)
  \( x = 1 / 4 \)
  \( x = 0.25 \)
• 3) \( 0.6x - 0.68 = 1 \)
  \( 0.6x = 1 + 0.68 \)
  \( 0.6x = 1.68 \)
  \( x = 1.68 / 0.6 \)
  \( x = 16.8 / 6 \)
  \( \begin{array}{c|cc cc} \multicolumn{2}{r}{2.8} \\ \cline{2-3} 6 & 16.8 \\ \multicolumn{2}{r}{12} \\ \cline{2-2} \multicolumn{2}{r}{48} \\ \multicolumn{2}{r}{48} \\ \cline{3-3} \multicolumn{2}{r}{0} \end{array} \)
  \( x = 2.8 \)

Ответ: 1) 4.7; 2) 0.25; 3) 2.8.