1) 3 1/2 * (1,6 * 1/24 * 5,25) : (47 * 1 2/47 : 10) = 0,25
1,6 * 1/24 = 16/240 = 1/15
1/15 * 5,25 = 1/15 * 21/4 = 21/60
3 1/2 * 21/60 = 7/2 * 21/60 = 147/120
47 * 1 2/47 = 47 * 49/47 = 49
49 : 10 = 4,9
147/120 : 4,9 = 147/120 * 10/49 = 3/12 = 1/4 = 0,25
2) 2 4/13 : (2 : (93,5 * 20/51 : 11)) : 10/13 * 0,04 = 0,2
93,5 * 20/51 = 935/10 * 20/51 = 1870/51 = 36 2/3
36 2/3 : 11 = 110/3 * 1/11 = 10/3 = 3 1/3
2 : 3 1/3 = 2 * 3/10 = 6/10 = 3/5
2 4/13 : 3/5 = 30/13 * 5/3 = 50/13
50/13 : 10/13 = 50/13 * 13/10 = 5
5 * 0,04 = 0,2
3 целых 3/4 * 1 целая 2/3+3 целых 3/4 *1/3=45/12*20/12+45/12*4/12=900/144+180/144=1080/144=135/18=7.5
253-(x-459)=138
x-459=253-138
x-459=115
x=459+115
x=574
----------------------------------------ПРОВЕРКА---------------------------------
253-(574-459)=138