Odpowiedź :
Szczegółowe wyjaśnienie:
a) 5 2/3 + 2 3/4= 5 8/12+ 2 9/12= 7 17/12= 8 5/12
b) 6 1/2 - 2 7/9= 6 9/18- 2 14/18= 5 27/18- 2 14/18= 3 13/18
c) 1 1/5 × 2 2/9= 6/5× 20/9= 8/3= 2 2/3
2/5 : 8= 2/5 : 8/1= 2/5× 1/8= 1/20
2 1/3 : 14= 7/3 : 14/1= 7/3× 1/14= 1/6
4 7/9 + 3 4/9= 7 11/9= 8 2/9
9 1/6 - 7 5/6= 8 7/6- 7 5/6= 1 2/6= 1 1/3
3 3/4 : 3 1/8= 15/4 : 28/8= 15/4× 8/25 = 6/5= 1 1/5.
1.
[tex]a) \ 5\dfrac{2}{3}+2\dfrac{3}{4} = 5\dfrac{8}{12}+2\dfrac{9}{12} =7\dfrac{17}{12} = 8\dfrac{5}{12}[/tex]
[tex]b) \ 6\dfrac{1}{2}-2\dfrac{7}{9} = 6\dfrac{9}{18}-2\dfrac{14}{18} = 5\dfrac{27}{18}-2\dfrac{14}{18} = 3\dfrac{13}{18}[/tex]
[tex]c) \ 1\dfrac{1}{5}\cdot2\dfrac{2}{9} = \dfrac{6}{5}\cdot\dfrac{20}{9} = \dfrac{6}{9}\cdot\dfrac{20}{5} = \dfrac{2}{3}\cdot4=\dfrac{8}{3} = 2\dfrac{2}{3}[/tex]
[tex]d) \ \dfrac{2}{5}:8 = \dfrac{2}{5}\cdot\dfrac{1}{8} = \dfrac{1}{5}\cdot\dfrac{1}{4} = \dfrac{1}{20}[/tex]
2.
[tex]a) \ 2\dfrac{1}{3}:14 = \dfrac{7}{3}\cdot\dfrac{1}{14} = \dfrac{1}{3}\cdot\dfrac{1}{2} =\dfrac{1}{6}[/tex]
[tex]b) \ 4\dfrac{7}{9}+3\dfrac{4}{9} = 7\dfrac{11}{9} = 8\dfrac{2}{9}[/tex]
[tex]c) \ 9\dfrac{1}{6}-7\dfrac{5}{6} = 8\dfrac{7}{6}-7\dfrac{5}{6} = 1\dfrac{2}{6} = 1\dfrac{1}{3}[/tex]
[tex]d) \ 3\dfrac{3}{4}:3\dfrac{1}{8} = \dfrac{15}{4}:\dfrac{25}{8} = \dfrac{15}{4}\cdot\dfrac{8}{25} = 3\cdot\dfrac{2}{5} = \dfrac{6}{5} = 1\dfrac{1}{5}[/tex]