0.2345²+0.7655²+2.469×0.7655
=0.2345^2+2*0.2345*0.7655+0.7655^2
=(0.2345+0.7655)^2
=1^2
=1是一減后面的。。漏掉了1-[0.2345²+0.7655²+2.469×0.7655]=1-[0.2345^2+2*0.2345*0.7655+0.7655^2]=1-(0.2345+0.7655)^2=1-1^2=(1+1)(1-1)=2*0=0減號后面加括號里面符號要變號吧。。我暈了 你的題目是：1-2345²+0.7655²+2.469×0.7655還是 1-0.2345²+0.7655²+2.469*0.7655還是1-（2345²+0.7655²+2.469×0.7655）還是啊1.2345²+0.7655²+2.469×0.7655~~~到底是哪一個？？1-0.2345²+0.7655²+2.469*0.7655=（1+0.2345）（1-0.2345）+0.7655+2.469*0.7655^2=（1.2345+0.7655+2.469）*0.7655=。。。。1.2345²+0.7655²+2.469×0.7655這個看我下樓的呵呵。。。。是1-23452+0.76552+2.469×0.76552345^2....這個還是用計算器算吧~~~我暈了 為啥不是1-0.2345^2