Răspuns:
[tex] \frac{8 \frac{8}{15}((0.2 + x( 1\frac{1}{3} - 1.2)) \times 1.(6) }{2.1(3)} = 4. \\ \frac{ \frac{128}{15} (( \frac{1}{5 } + x( \frac{4}{3} - \frac{6}{5} ) )\times \frac{5}{3} }{ \frac{192}{90} } = 4. \\ \\ \frac{128}{15} ( \frac{1}{5} + \frac{2x}{15} ) \times \frac{5}{3} = 4 \times \frac{192}{90} \\ \frac{128}{15} \times \frac{2x + 3}{15} \times \frac{5}{3} = \frac{256}{30} \\ \frac{640(2x + 3)}{675} = \frac{256}{30} \\ 1280x + 1920 = 5760 \\ 1280x = 3840 \\ x = 3[/tex]
