4.35×99+20分之7＋4=(4+0.35)×99+0.35+4 =4×99+0.35×99+0.35+4 =4×(99+1)+0.25×(99+1) =400+25 =425 1-（7分之5+14分之3除于4分之3）×7分之2 =1-(5/7+3/14×4/3)×2/7 =1-(5/7+2/7)×2/7 =1-2/7 =5/7