Найдите неизвестный член пропорции. 6 1/2:x=6 5/6 :4,1 0,38:x=4 3/4:1 7/8

1) х * 4,1 * 6 1/2 : x = х * 4,1 * 6 5/6 : 4,1;

41/10 * (6 * 2 + 1)/2 = х * (6 * 6 + 5)/6;

41/10 * 13/2 = х * 41/6;

х = (41 * 13)/20 : 41/6 = (41 * 13)/20 * 6/41 = 13 * 6/20 = 39/10 = 3,9;

2) 1 7/8 * х * 0,38 : x = 1 7/8 * х * 4 3/4 : 1 7/8;

(1 * 8 + 7)/8 * 0,38 = х * (4 * 4 + 3)/4;

15/8 * 38/100 = х * 19/4;

х = (15 * 38)/(8 * 100) : 19/4 = (3 * 19)/(4 * 20) * 4/19 = 3/20;

3) 5/11 * 10,4 = x * 3 5/7;

х = (5 * 104)/(11 * 10) : (3 * 7 + 5)/7 = 52/11 * 7/26 = 14/11;

4) 1,25 : 1,4 = 0,75 : x;

х = 1,4 * 0,75/1,25 = 0,84;

5) 3 1/2 : 0,4 = x : 1 1/7;

х = (3 * 2 + 1)/2 * (1 * 7 + 1)/7 : 4/10 = 7/2 * 8/7 * 10/4 = 10;

6) 15,6 : 2,88 = x : 14 2/5;

х = 15,6 * (14 * 5 + 2)/5 : 288/100 = 156/10 * 72/5 * 100/288 = 78.