Sagot :
[tex]\frac{7}{10}-\frac{1}{2}=\frac{7}{10}-\frac{1\cdot5}{2\cdot5}=\frac{7}{10}-\frac{5}{10}=\frac{2}{10}=\frac{2:2}{10:2}=\frac{1}{5}\\\\\\------------------------------\\\\\frac{7}{10}-\frac{1}{2}=0.7-0.5=0.2[/tex]
[tex]7/10\ minus\ 1/2= \frac{7}{10} - \frac{1}{2} = \frac{7}{10} - \frac{1\cdot5}{2\cdot5}=\frac{7}{10} - \frac{5}{10} =\frac{2}{10}=\frac{1}{5} [/tex]