0.99x14+9.9x8.6
=0.99x1.4+0.99x8.6
=0.99x(1.4+8.6)
=0.99x10
=9.9
0.99*14=(1-0.01)*14=14-0.14
9.9*8.6=(10-0.1)*8.6=86-0.86
:9.9×9.9+0.99=99x0.99+0.99=0.99x(99+1)=0.99x100=99
0.99×149.9×8.6
=0.99×(150-0.1)×8.6
=0.99×(150×8.6-0.86)
=0.99×(1290-0.86)
=(1-0.01)(1290-0.86)
=1290-0.86-12.9+0.0086
=1290-13.76+0.0086
=1276.24+0.0086
=1276.2486