123/350-53/350=70/350=1/5
39/350+11/350=50/350=1/7
107/420+103/420=210/420=1/2
<span>287/420-117/420=170/420=17/42</span>
....... = 15х - х + 3,14 = 25
15х -(х +3,14) = 25
15х - х - 3,14 = 25
14х = 28,14
х = 2,01
2кг*28=56р1 3/4кг=1,75кг*28=49р2 1/2кг=2,5кг*28=70р3/4=0,75*28=21р<span>2/5=0,4кг*28=11,2р=11р 20коп</span>