Доброе утро всем! с уравнениями! 42567÷а=357-350 (х+10)÷370=20 900÷(х+5)=100

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42567:а=7
а=42567:7
а=6081
42567÷6081=357-350
(х+10):370=20
(х+10)=370×20
(х+10)=7400
х=7400-10
х=7390
(7390+10):370=20
20=20
900 :(х+5)=100
(х+5)=900:100
×+5=9
х=9-5
х=4
900÷(4+5)=100
100=100