Bonjour,
a)
4 x 15 x 14 = 840
21 x 10 x 22 = 4620
840 = 2 x 2 x 2 x 5 x 7 x 3 = 2³ x 5 x 7 x 3
4620 = 2 x 2 x 5 x 3 x 7 x 11 = 2² x 5 x 3 x 7 x 11
[tex]\frac{840}{4620}[/tex] = [tex]\frac{2 * 2 * 2 * 5 *7 * 3}{2 *2 *5 *3 * 7 *11 }[/tex] = [tex]\frac{2}{11}[/tex]
b)
[tex]\frac{2*2*3*5*5*5}{2*3*3*3*5*5}[/tex] = [tex]\frac{2*5}{3*3}[/tex] = [tex]\frac{10}{9}[/tex]
