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х+4у = а4-а/2 = а/3-1а/3-а/2 = 4+1-а/3 = 5а = -15х+4у = -15х = -15-4у6х-2у+4+7х+28у = 5613х+26у = 52-195-52у+26у = 52-26у = 247у = 9.5х = -15-4*9.5 = -15-38 = -53х*(у+7) = -53*16,5 = -874,5Ответ: -874,5