320-x=20please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please
320-x=20
x=320-20
x=300
320-300=20
20=20
Удачи)))
х=20-320
х=-300
как то так