x + 20 = 200 + 100
x + 20 = 300
x = 300 - 20
x = 280
x + 20 = 200 + 100
x + 20 = 300
x =300 - 20
x = 280
x+20=200+100
x+20=300
x =300-20
x =280.
Tk mk nhé!
x + 20 = 200 + 100
x + 20 = 300
x = 300 - 20
x = 280
x + 20 = 200 + 100
x + 20 = 300
x = 300 - 20
x = 280