423+12*x=507
448:(123-x)=8
Решите уравнения

423+12*x=507  

12x = 507 - 423

12x = 84

x = 84 : 12

x = 7

448:(123-x)=8

123 - x = 448 : 8

123 - x = 56

x = 123 - 56

x = 67