(x+15)-8=17(24+x)-21=10(45-y)+18=58(y-35)+12=3256-(x+12)=2455-(x-15)=30

(х + 15) - 8 = 17        (24 + х) - 21 = 10       (45 - у) + 18 = 58х + 15 = 17 + 8           24 + х = 10 + 21        45 - у = 58 - 18х + 15 = 25                 24 + х = 31                45 - у = 40х = 25 - 15                  х = 31 - 24                у = 45 - 40х = 10                         х = 7                          у = 5(у - 35) + 12 = 32      56 - (х + 12) = 24      55 - (х - 15) = 30  у - 35 = 32 - 12          х + 12 = 56 - 24        х - 15 = 55 - 30у - 35 = 20                 х + 12 = 32               х - 15 = 25у = 20 + 35                х = 32 - 12                х = 25 + 15у = 55                        х = 20                        х = 40