Question

1) 8,5-1/3; 2) 4 1/9+1,8; 3) 1/9×0,12; 4) 6/7÷0,6

Answer 1

1)

$8,5-\dfrac{1}{3}=\dfrac{85}{10}-\dfrac{1}{3}=\dfrac{17}{2}-\dfrac{1}{3}=\dfrac{51}{6}-\dfrac{2}{6}=\dfrac{49}{6}=\boldsymbol{8\dfrac{1}{6}}$

2)

$4\dfrac{1}{9}+1,8=4\dfrac{1}{9}+\dfrac{18}{10}=4\dfrac{1}{9}+\dfrac{9}{5}=4\dfrac{1}{9}+1\dfrac{4}{5}=5\dfrac{5+36}{45}=\boldsymbol{5\dfrac{41}{45}}$

3)

$\dfrac{1}{9}\cdot 0,12=\dfrac{1}{9}\cdot \dfrac{12}{100}=\dfrac{1}{9}\cdot \dfrac{3}{25}=\dfrac{1}{3\cdot 25}=\boldsymbol{\dfrac{1}{75}}$

4)

$\dfrac{6}{7}:0,6=\dfrac{6}{7}:\dfrac{6}{10}=\dfrac{6}{7}\cdot \dfrac{10}{6}=\dfrac{10}{7}=\boldsymbol{1\dfrac{3}{7}}$

Answer 2

$8.5 - \frac{1}{3} = \frac{17}{2} - \frac{1}{3} = \frac{49}{6} = 8 \frac{1}{6} \\ \\ 4 \frac{1}{9} + 1.8 = \frac{37}{9} + \frac{9}{5} = \frac{266}{45} = 5 \frac{41}{45} \\ \\ \frac{1}{9} \times 0.12 = \frac{1}{9} \times \frac{3}{25} = \frac{1}{3} \times \frac{1}{25} = \frac{1}{75} \\ \\ \frac{6}{7} \div 0.6 = \frac{6}{7} \div \frac{3}{5} = \frac{6}{7} \times \frac{5}{3} = \frac{2}{7} \times 5 = \frac{10}{7} = 1 \frac{3}{7}$