Bonsoir,
a)[tex]\frac 45 \times \frac{35}9 = \frac 45 \times \frac {7\times 5}{9} = 4\times \frac 79 = \frac {28}{9}[/tex]
b)[tex]\frac 34 \times \frac{11}{5} = \frac{3\times 11}{4\times 5} = \frac{33}{20}[/tex]
c)[tex]\frac{7}{10} \times \frac{9}{4} =\frac{7\times 9}{10\times 4} = \frac{63}{40}[/tex]
