Подготовка к контрольной работе

Вычислим:

1. а) $$3 - 1\frac{4}{11} = 3 - \frac{15}{11} = \frac{33}{11} - \frac{15}{11} = \frac{18}{11} = 1\frac{7}{11}$$

2. б) $$11\frac{3}{11} + 2\frac{5}{22} = 11\frac{6}{22} + 2\frac{5}{22} = 13\frac{11}{22} = 13\frac{1}{2}$$

3. в) $$-6\frac{4}{9} + 2\frac{1}{6} = -6\frac{8}{18} + 2\frac{3}{18} = -4\frac{5}{18}$$

4. г) $$\frac{-5}{17} : \frac{15}{34} = \frac{-5}{17} \cdot \frac{34}{15} = \frac{-5 \cdot 34}{17 \cdot 15} = \frac{-1 \cdot 2}{1 \cdot 3} = -\frac{2}{3}$$

5. д) $$3\frac{1}{8} : 1\frac{1}{4} = \frac{25}{8} : \frac{5}{4} = \frac{25}{8} \cdot \frac{4}{5} = \frac{25 \cdot 4}{8 \cdot 5} = \frac{5 \cdot 1}{2 \cdot 1} = \frac{5}{2} = 2\frac{1}{2}$$

6. e) $$-4\frac{4}{15} - 2\frac{11}{20} = -4\frac{16}{60} - 2\frac{33}{60} = -6\frac{49}{60}$$

7. ж) $$38{,}5 - 6{,}951 = 31{,}549$$

8. з) $$8{,}03 \cdot 2{,}4 = 19{,}272$$

9. и) $$0{,}00058 : 0{,}8 = 0{,}000725$$

10. к) $$16{,}24 : 1{,}6 = 10{,}15$$

11. л) $$0{,}012 \cdot 3{,}8 = 0{,}0456$$