8) 20: 4 9) 12 : 3 10) 13: 13 11) 46 23 12) 60 : 2 _ _ _ _ _ 9 4 15 31 19

Решите задачу:

$20: \frac{4}{9}= \frac{20}{1}* \frac{9}{4}= \frac{5*9}{1*1}=45$

$12: \frac{3}{4}= \frac{12}{1}* \frac{4}{3}= \frac{4*4}{1*1}=16$

$13: \frac{13}{15}= \frac{13}{1}* \frac{15}{13}= \frac{1*15}{1*1}=15$

$46: \frac{23}{31}= \frac{46}{1}* \frac{31}{23} = \frac{2*31}{1*1}= 62$

$60: \frac{2}{19}= \frac{60}{1}* \frac{19}{2}= \frac{30*19}{1*1}=570$