用递等式计算下列各题，能简算的要简算．
①37×40+1035÷23                       ②86.5×2.4÷0.3﹣690
③2.8+[2.4÷（90﹣60）]                  ④46.5×43.5+43.5×27.5﹣25×43.5
⑤×+×                         ⑥0.4×7+×3﹣0.4×3．