初一简便计算1.2345^2+0.7655^2+2.469*0.7655
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初一简便计算
1.2345^2+0.7655^2+2.469*0.7655
1.2345^2+0.7655^2+2.469*0.7655
![初一简便计算1.2345^2+0.7655^2+2.469*0.7655](/uploads/image/z/15342003-27-3.jpg?t=%E5%88%9D%E4%B8%80%E7%AE%80%E4%BE%BF%E8%AE%A1%E7%AE%971.2345%5E2%2B0.7655%5E2%2B2.469%2A0.7655)
这个其实是完全平方公式的逆运算
a^2+b^2+2ab=(a+b)^2
1.2345^2+0.7655^2+2.469*0.7655
=1.2345^2+0.7655^2+2*1.2345*0.7655
=(1.2345+0.7655)^2
=2^2
=4
a^2+b^2+2ab=(a+b)^2
1.2345^2+0.7655^2+2.469*0.7655
=1.2345^2+0.7655^2+2*1.2345*0.7655
=(1.2345+0.7655)^2
=2^2
=4