Question

1) 2)

4/7 = 8/14; b/5 = 6/15;

3/4 = 12/20. 10/b = 30/33

Answer 1

1)4/7=8/14  ; b/5=6/15  b=6/15*5=6/3=2  b=2

2)3/4=12/20 тут ошибка,должно быть 3/5=12/20 ;10/b=30/33 b=10/30/33 =10*33/30 =33/3= 11       b=11