[tex]1 \frac{3}{7} * 5 \frac{4}{3} = \frac{10}{7} * \frac{19}{3} = \frac{190}{21} \approx 9,0476..[/tex]
When he simplified the expression:
[tex]1 \frac{1}{2} *6= \frac{3}{2} * \frac{6}{1} = \frac{18}{2} = 9[/tex]
[tex]9,047 \approx 9,05 \approx 9[/tex]
I think Joseph's estimate a close estimate.
