a)80-[130-(12-40)2] b)27.75+25.27-150 c)12:{390:[500-(125+35.7)]}
=80-[130-(-28)2] =27.(75+25)-150 =12:{390:[500-(125+245)]}
=80-[130-784] =27.100-150 =12:{390:[500-370]}
=80-(-654) =2700-150 =12:{390:130}
=80+654 =2550 =12:3
=734 =4
Nhớ **** thanks so much^__^