(1+0.4567+0.5678)×(0.4567+0.5678+0.6789)－(1+0.4567+0.5678+0.6789)×(0.4567+0.5678）＝

题目

(1+0.4567+0.5678)×(0.4567+0.5678+0.6789)－(1+0.4567+0.5678+0.6789)×(0.4567+0.5678）＝

答案

设0.4567+0.5678=t
则：
原式=(1+t)(t+0.6789)-(1+t+0.6789)*t
=t(1+t)+0.6789(1+t)-t(1+t)-0.6789t
=0.6789