4. Рашыце ўраўненне: 5,4: (0,3x + 1) = 1,8

Рашэнне:

1. $$ 5,4:(0,3x + 1) = 1,8 $$
2. $$ 0,3x + 1 = 5,4 : 1,8 $$
3. $$ 0,3x + 1 = 3 $$
4. $$ 0,3x = 3 - 1 $$
5. $$ 0,3x = 2 $$
6. $$ x = 2 : 0,3 $$
7. $$ x = \frac{2}{0,3} $$
8. $$ x = \frac{20}{3} $$
9. $$ x = 6\frac{2}{3} $$

Адказ: $$ x = 6\frac{2}{3} $$