1) 3 7/25 +2,72= 3,28+2,72 =6
2) 6 * 5/24 = 5/4
3) 15/16 : 3 3/4 =15/16 * 4/15 = 1/4
4) 1/4 - 2/9 = 9/36 - 8/36 = 1/36
5)5/4 : 1/36 =5/4 *36 = 45
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6) 0,224:0,35=0,64
7) 0,36 + 0,64 = 1
8) 1*5=5
9) 5,85:1 19/20 = 5,85:1,95=3
10) 3 - 2 5/9 = 4/9
11) 4/9:4 = 4/9 *1/4=1/9
12) 5 : 1/9 = 5*9=45
13) 45-45 =0