mik viết nhầm là:
100 + 500 + 400 : 2 = 100 + 500 + 200
= 600 + 200
= 800
100+500+400:2
=100+500+200
=600+200
=800
100 + 500 + 400 : 2= 600 + 400 : 2
= 1000 : 2 = 500
100 + 500 + 400 : 2
= 100 + 500 + 200
= 800 nha bn
100+500+400:2
=100+500+200
=800