500 - x = 200 + 100
500 - x = 300
x = 500 - 300
x = 200
500 - x = 200 + 100
500 - x = 300
x = 500 - 300
x = 200
500 - x = 200 + 100
500 - x = 300
x = 500 - 300
x = 200
ai k minh thi minh k lai
500 - x = 200 + 100
500 - x = 300
x = 500 - 300
x = 200
500 - x = 200 + 100
500 - x = 300
x = 500 - 300
x = 200
500 - x = 200 + 100
500 - x = 300
x = 500 - 300
x = 200