la so 77071067812
12345 + 12345 + 12345 + 12345
= 12345 x 4
= 49380
1493 moi dung cac ban a
a=12
b=30 nha bạn.
k nha.thanks
x - 100 = 670 - 70
x - 100 = 600
x = 600 + 100
x = 700
x-100=600
x=600+100
x=700