Найдите значение выражения 2/9 + 4/9

1. **Ответ: $\frac{2}{3}$** $$\frac{2}{9} + \frac{4}{9} = \frac{6}{9} = \frac{2}{3}$$ 2. **Ответ: $4,5$** $$\frac{19}{7} : \frac{38}{63} = \frac{19}{7} \cdot \frac{63}{38} = \frac{1 \cdot 9}{1 \cdot 2} = \frac{9}{2} = 4,5$$ 3. **Ответ: $22$** $$\left(1\frac{2}{7} - \frac{1}{2}\right) \cdot 28 = \left(\frac{9}{7} - \frac{1}{2}\right) \cdot 28 = \left(\frac{18-7}{14}\right) \cdot 28 = \frac{11}{14} \cdot 28 = 11 \cdot 2 = 22$$ 4. **Ответ: $6,5$** $$\frac{17,1 - 2,8}{2,2} = \frac{14,3}{2,2} = \frac{143}{22} = 6,5$$ 5. **Ответ: $28,8$** $$6,5 \cdot 4,8 - 2,4 = 31,2 - 2,4 = 28,8$$ 6. **Ответ: $1,95$** $$-3,25 \cdot (-4,2 + 3,6) = -3,25 \cdot (-0,6) = 1,95$$ 7. **Ответ: $x = 3$** $$3(3 - 2x) + 8 + 2x = 5$$ $$9 - 6x + 8 + 2x = 5$$ $$-4x + 17 = 5$$ $$-4x = 5 - 17$$ $$-4x = -12$$ $$x = 3$$ 8. **Ответ: $x = -1,5$** $$5(x - 2,4) = 13x$$ $$5x - 12 = 13x$$ $$5x - 13x = 12$$ $$-8x = 12$$ $$x = -\frac{12}{8}$$ $$x = -1,5$$ 9. **Ответ: $x = 0,5$** $$7 - 4(6x - 2) = 3$$ $$7 - 24x + 8 = 3$$ $$15 - 24x = 3$$ $$-24x = 3 - 15$$ $$-24x = -12$$ $$x = \frac{12}{24}$$ $$x = 0,5$$