简便计算过程方法如下解:78×22+39×56=1716+39×56=39×44+39×56=39×(44+56)=39×100=3900
78×22+39×56=39×2×22+39×56=39×(44+56)=39×100=3900
原式=1716+39×56=39×44+39×56=39×(44+56)=39×100=3900