问题补充说明:简便计算(1)12×98×5÷49(2)28.2×44.54+4.454×718(3)22.4×956-1.2×3(4)(49-67)-(17-23)_____
(1)12×98×5÷49=12×5×(98×14供儿急肉脚可岁9)
=60×2
=120;
(2)28.2×44.54+4.454×718
=28.2×44.54+44.54×71.8
=(2360问答8.2+71.8)×44.那点54
=100×44.54
=4454;
(3)22.4×956-1.2×3
=3虽机绝.6-3.6
=0;
(4)(49-67)-(17-23)
=49-殖击67-17+23
=49+23-(67+17)
=109-1
选西凯国背露断=19.