872-(72+89)
=872-72-89
=800-89
=711
78×37+24×37
=(78+24)×37
=102×37
=100×37+2×37
=3700+74
=3774
由题意可以知道,
872-(72+89)=872-72-89=800-89=711,
78×37+24×37=(78+24)×37=102×37=(100+2)×37=100×37+2×37=3700+74=3774。
872-(72+89)
=872-72-89
=800-89
=711
78x37+24x37
=(78+24)x37
=102ⅹ37
=(100+2)ⅹ37
=100ⅹ37+2x37
=3700+74
=3774
872-72-89=711
(78+22)×37+2×37=3774