怎么简便计算?第一道题7.2×5.8+0.72×42第二道题9.76×0.72-0.76×0.72+0.72第三道题27×3.7+3.7×75 急

问题描述:

怎么简便计算?第一道题7.2×5.8+0.72×42第二道题9.76×0.72-0.76×0.72+0.72第三道题27×3.7+3.7×75 急

0.72*58+0.72*42=0.72*(58+42)=0.72*100=72
0.72*(9.76-0.76+1)=0.72*10=7.2
3.7*(27+75)=3.7*(100+2)=370+7.4=377.4