(1)350×[(120-60)÷15]=350×[60÷15]=350×4=1400(2)480÷(40+40)×2=480÷80×2=6×2=12(3)936÷[6×(18-5)]=936÷[6×13]=936÷78=12(4)(1230+270)÷30×26=1500÷30×26=50×26=1300