27.38-5.34+2.62-4.66=(27.38+2.62)-(5.34+4.66)=30-10=20
15.7-4.3+3.54+4.3=15.7+3.54+(4.3-4.3)=15.7+3.54=19.24
27.38-5.34+2.62-4.66
=(27.38+2.62)-(5.34+4.66)
=30-10
=20
15.7-4.3+3.54+4.3
=15.7+3.54+4.3-4.3
=15.7+3.54
=19.24
=27.38+2.62-(5.34+4.66)
=5-10
=5
第一题=(27.38+2.62)-(5.34+4.66)=30-10=20
第二题 =15.7+3.54+(4.3-4.3)=19.24
15.7-4.3+3.54+4.3=15.7+3.54-4.3+4.3=19.24
27.38-5.34+2.62-4.66=27.38+2.62-5.34-4.66=30-(5.34+4.66)=30-10=20
2010-10-17 16:50
27.38-5.34+2.62-4.66
=(27.38+2.62)-(5.34+4.66)
=30-10
=20
15.7-4.3+3.54+4.3
=15.7+3.54+4.3-4.3
=15.7+3.54
=19.24
15.7-4.3+3.54+4.3=15.7+3.54-4.3+4.3=19.24
27.38-5.34+2.62-4.66=27.38+2.62-5.34-4.66=30-(5.34+4.66)=30-10=20
第一题=(27.38+2.62)-(5.34+4.66)=30-10=20
第二题 =15.7+3.54+(4.3-4.3)=19.24
第二题你是不是题目写错了?