计算下面各题，能简算的要简算

①3.4×12.5×0.08

②42.6×0.8﹣21.5

③6.8×2.7+2.7×3.2

④1.29÷6.45×26

⑤36.7÷1.25÷8

⑥3.6+6.4×0.35