1500.17=25500
25500:1700=15
vay ?=25500
a=15
chuc bn hoc gioi!
1500x17
=1500x(10+7)
=1500x10+1500x7
=15000+10500
=25500
1700=200-300
?=1500x17=25500
a=?:1700=25500:1700=15
k nha
1500x17 = ? => ? = 25500
Từ ? = 25500 => ? : 1700 = 25500 : 1700 = 15 = a
Vậy ? = 25500; a = 15