第1个回答 2013-07-12
解:
2^2x=12
4^x=12
x=根号12/4
x=0.866
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第2个回答 2013-07-12
2^(2X)=12
log(2^(2X))=log 12
(2X)*log 2=log 12
2X=(log 12)/(log 2)=3.5849625
X=3.5849625/2=1.79248125
第3个回答 2013-07-12
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第4个回答 2013-07-12
2^(2x)=12
两边取lg
2xlg2=l12=lg4+lg3=2lg2+lg3
2x=2+(lg3)/(lg2)
x=1+(1/2(lg3)/(lg2)=1+(1/2)(0.4771)/(0.3010)
第5个回答 2013-07-12
解:2^2x=12
4^x=12
x≈1.792481250361