Ответ:

  1. \(0.5x=6\)
    \(x=6:0.5=12\)
  2. \(1.2y=9.6\)
    \(y=9.6:1.2=8\)
  3. \(\frac{x}{0.3}=7\)
    \(x=7\cdot0.3=2.1\)
  4. \(\frac{y}{0.8}=12\)
    \(y=12\cdot0.8=9.6\)

Ответ: x = 12; y = 8; x = 2,1; y = 9,6.