1.25×﹙7.4×9﹚
=1.25×7.4×(8+1)
=1.25×7.4×8+1.25×7.4×1
=10×7.4+1.25×7.4
=74+1.25×(8-0.6)
=74+1.25×8-1.25×0.6
=74+10-0.75
=83.25