用简便方法计算下列各题,我很急,在线等,谢谢!

1.8×19.2-3.6×4.6
=1.8x19.2-1.8x2x4.6
=1.8x(19.2-9.2)
=1.8x10
=18
3.2×1.85+1.6×16.3
=1.6x2x1.85+1.6x16.3
=1.6x(3.7+16.3)
=1.6x20
=32
6.38×9.9+33×3.62×0.3
=6.38x9.9+9.9x3.62
=9.9x(6.38+3.62)
=9.9x10
=99