4307一25×（525÷15）＝4307一25×525÷5÷3＝4307－25÷5×（525÷3）＝4307－5×175＝4307一5×100一5×70－5×5＝4307－500一（350＋25）＝3807－375＝3807＋5－380＝3812一380＝3432
