500 + x = 400 + 200
500 + x = 600
x = 600 - 500
x = 100
500+x=400+200
500+x=600
x =600-500
Vay x=100 la gtri can tim
500+X=400+200
500+X=600
X=600-500
X=100
X = 100
Vì
500 + x = 600 thì
x = 600 - 500
X = 100
500 + x = 400 + 200
500 + x = 600
x = 600 - 500
x = 100
500 + x = 400 + 200
500 + x = 600
x = 600 - 500
x = 100
500 + x = 400 + 200
500 + x = 600
x = 600 - 500
x = 100