41.2*8.1+11*1.25+537*0.19
=(41.2×10 - 412×1.9 + 11×125 + 537×0.19)
=412 + 11×1.25 + (537 - 412)×0.19]
=412 + 11×1.25 + 125×0.19)
=412 + (11 + 19)×1.25
=412 + 30 × 1.25
=412 + 37.5
=449.5