Помогите пожалуйста,математика ,дробление дробейОчень безотлагательно

все?

78
1) 3/4 : 5/7 = 3/4 * 7/5 = 21/20 = 1 1/20
2) 5/18 : 25/27 = 5/18 * 27/25 = 1/2 * 3/5 = 3/10
3) 9/16 : 3/64 = 9/16 * 64/3 = 3/1 * 4/1 = 3/4
4) 25/72 : 45/63 = 25/72 * 63/45 = 5/8 * 7/9 = 35/72 
79
8 : 4/5 = 8/1 * 5/4 = 2 * 1 = 2
1 : 7/16 = 1/1 * 16/7 = 16/7 = 2 2/7
8/15 : 24 = 8/15 * 1/24 = 1/15 * 1/3 = 1/45
12 1/2 : 3 3/4 = 25/2 : 15/4 = 25/2 * 4/15 = 5/1 * 2/3 = 10/3 = 3 1/3
1 3/5 : 5 1/3 = 8/5 : 16/3 = 8/5 * 3/16 = 1/5 * 3/2 = 3/10 = 0,3
2 5/8 : 7/32 = 21/8 : 7/32 = 21/8 * 32/7 = 3/1 * 4/1 = 12
80
1) 2 1/4 : 3/8 : 1/ 2 = 9/4 * 8/3 * 2/1 = 3/1 * 2/1 * 2/1 = 12
2) 2 1/4 : (3/8 : 1/2) = 9/4 : (3/8 * 2/1) = 9/4 : 6/8 = 9/4 * 8/6 = 3/1 * 2/2 = 3
3) (6 3/4 - 5 1/8 : 1 9/32) : 2 1/5 = 5/4 = 1 1/4
         1) 5 1/8 : 1 9/32 = 41/8 : 41/32 = 41/8 * 32/41 = 1/1 * 4/1 = 4
          2) 6 3/4 - 4 = 6 3/4 - 3 4/4 = 5 7/4 - 3 4/4 = 2 3/4
          3) 2 3/4 : 2 1/5 = 11/4 : 11/5 = 11/4 * 5/11 = 5/4
4) (3 1/4 + 2 1/6) : 2 3/5 - 2/3  : 4/9 = 11
           1) 3 1/4 + 2 1/6 = 3 3/12 + 2 2/12 = 5 5/12
            2) 5 5/12 : 2 3/5 = 65/12 : 13/5 = 65/12 * 5/13 = 5/12 * 5/1 = 25/2
            3) 2/3 : 4/9 = 2/3 * 9/4 = 1/1 * 3/2 = 3/2
             4) 25/2 - 3/2 = 22/2 = 11
81
1) 6/5х = 3/5
     х = 3/5 : 6/5
     х = 3/5 * 5/6
     х = 1/2
2) 4/7х = 1
    х = 1 : 4/7
    х =  7/4 = 1 3/4
3) 3/4х = 12
    х = 12 : 3/4
    х = 12/1 * 4/3
    х = 16
4) 3х = 2/3
     х = 2/3 : 3
     х = 2/3 * 1/3
     х = 2/9
5) х : 7/15 = 15/28
    х = 15/28 * 7/15
    х = 1/4
6) 5 1/4 : х = 7/8
    х = 5 1/4 : 7/8
    х = 21/4 : 7/8
    х = 21/4 * 8/7
    х = 3/1 * 2/1
    х = 6