用递等式计算，能简算的要简算，写出主要过程．
③ 32×1.25                          ②500﹣769.6÷3.7+20
③4+67.2+5+32.8                 ④（+）×18+×1
⑤÷（4﹣2.4×）                 ⑥1110÷[56×（﹣）]．