7.29乘4.6加46乘1.271
=0.729×46+46×1.271
=(0.729+1.271)×46
=2×46
=92
9.6乘3.6加8.2乘0.2
=9.6×9×0.4+4.1×0.4
=(9.6×9+4.1)×0.4
=90.5×0.4
=36.2