⑴5795.5795/5.795*579.5 ⑵45.3*3.2+578*0.68+12*9.5 ⑶88.8/3.14*62.8*_数学解答

⑴5795.5795/5.795*579.5 ⑵45.3*3.2+578*0.68+12*9.5 ⑶88.8/3.14*62.8*24.3/8/8.1
⑷0.1949*0.19951995-0.1995*0.19491949 ⑸18.9*178.178+0.49-17.8*189.189
⑹3.42*76.3+76.3*5.76+9.18*23.7
要简便算法！

人气：389 ℃　时间：2020-05-15 00:46:22

解答

（4）0.1949*0.19951995-0.1995*19491949=0.1949*（0.1995+0.00001995）-0.1995*（0.1949+0.00001949）
用乘法分配律：0.1949*（0.1995+0.00001995）-0.1995*（0.1949+0.00001949）=0.1995*（0.1949+0.00001949）-0.1995*（0.1949+0.00001949）=0.1995*（0.1949+0.00001949-0.1949-0.00001949）=0.1995*0=0