用递等式计算（能简算的请简算）．①21.7+153÷17×0.8②12.5×（2.3+2.3+2.3+2.3）③（45+14）÷37+910④7.8×4.5+78×0.55⑤15.84÷[8×（8.24-6.59）]⑥89×[34-（516-14）]．

Question

用递等式计算（能简算的请简算）．

①21.7+153÷17×0.8	②12.5×（2.3+2.3+2.3+2.3）
③（(4)/(5)+(1)/(4)）÷(3)/(7)+(9)/(10)	④7.8×4.5+78×0.55
⑤15.84÷[8×（8.24-6.59）]	⑥(8)/(9)×[(3)/(4)-（(5)/(16)-(1)/(4)）]．

Answer 1

①21.7+153÷17×0.8=21.7+9×0.8=21.7+7.2=28.9；②12.5×（2.3+2.3+2.3+2.3）=12.5×2.3×4=12.5×4×2.3=50×2.3=115；③（45+14）÷37+910=2120÷37+910=4920+910=6720；④7.8×4.5+78×0.55=7.8×4.5+7.8×5.5=...