下面各题怎样简便就怎样算.(1)3.7×99+3.7 (2)×7.7+3.3×0.75﹣75%(3)5.93+0.64+0.07+0.36 (4)(7.9﹣3.06÷0.68)×1.5(5)78÷2.5÷0.4 (6)105×(+)