Ответ:

[tex]( \frac{2}{3} x - 0.8) \times 15 = 8[/tex]

[tex]10x - 12 = 8 \\ 10x = 12 + 8 \\ 10x = 20 \\ x = 2[/tex]

б)

[tex]7.2 \div 2.4 = 0.9 \div x \\ 0.9 \div x = 7.2 \div 2.4 \\ 0.9 \div x = 3 \\ x = 0.9 \div 3 \\ x = 0.3[/tex]