问一道数学题79.31×0.6783×0.25＋23.56＋6.783×7.931×0.75－0.125×0.7931×67.83×86.8×0.32＋0.32×4.2－8÷25、28.67×67＋3.2×286.7＋573.4×0.05请把过程写下来!要求巧算!

Answer 1

79.31×0.6783×0.25＋23.56＋6.783×7.931×0.75－0.125×0.7931×67.83×8
=79.31×0.6783×0.25＋23.56＋0.6783×79.31×0.75－0.125×8×0.7931×67.83
=79.31×0.6783×（0.25+0.75）+23.56-0.7931×67.83
=79.31×0.6783+23.56-79.31×0.6783
=23.56
6.8×0.32＋0.32×4.2－8÷25
= 6.8×0.32＋0.32×4.2－0.32
=0.32×（6.8+4.2-1）
=0.32×10
=3.2
28.67×67＋3.2×286.7＋573.4×0.05
=28.67×67＋32×28.67＋28.67
=28.67×（67+32+1）
=28.67×100
=2867