Bonjour
a )
[tex] \frac{5}{7} \times \frac{2}{3} = \frac{5 \times 2}{7 \times 3} = \frac{10}{21} [/tex]
b)
[tex] \frac{9}{11} \times \frac{8}{7} = \frac{9 \times 8}{11 \times 7} = \frac{72}{77} [/tex]
c)
[tex] \frac{45}{7} \times \frac{2}{9} = \frac{45 \times 2}{7 \times 9} = \frac{90}{63} = \frac{10 \times 9}{7 \times 9} = \frac{10}{7} [/tex]
d)
[tex] \frac{6}{7} \times \frac{1}{13} = \frac{6}{91} [/tex]
bonne journée
