1)х=0,25х12/0,75=3/0,75=4
2)х=0,75х5/0,36=3,75/0,36=10,416666
3)х=3х0,12/0,5=0,36/0,5=0,72
4)х=4х0,4/3,2=1,6/3,2=0,5
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(это проверка)

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4) 


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