1) В

[tex]9x = - 54 \\ x = - 54 \div 9 \\ x = - 6[/tex]

2) Г

[tex] - 3.78 \div x = - 0.6 \\ 3.78 \div x = 0.6 \\ x = 3.78 \div 0.6 \\ x = 6.3[/tex]

3) А

[tex]18 \div ( - x) = 0.6 \\ - x = 18 \div 0.6 \\ - x = 30 \\ x = - 30[/tex]