250 + 150 + 100 = 500
1 + 1 + 1 + 1 + 1 + 1 +1 = 7
9 x 3 - 21 = 6
100 km - 250 km = 750 km
7 x 5 = 35
250+150+100=500
1+1+1+1+1+1+1=1x7=7
9x3-21=27-21=6
1000km - 250 km = 750 km
7x5 =35
250+150+100=500
1+1+1+1+1+1+1=1*7=7
1000km-250km=750
7*5=35
Câu 1 : 500
Câu 2 : 7
Câu 3 : 6
Câu 4 : 750 km
Câu 5 : 35
=500 =7 =6 =750 km =35