Summer Clouds moderators
15/11/2017 at 08:32-
Bảo Bình 15/11/2017 at 12:09
We have:\(2^{18}=4^x\Leftrightarrow2^{18}-4^x=0\Leftrightarrow\left(2^2\right)^9-4^x=0\Leftrightarrow4^9-4^x=0\)
\(\Leftrightarrow4^z\left(4^{9-x}-1\right)=0\).Because 4x>0 so 49-x=1\(\Rightarrow9-x=0\Rightarrow x=9\)
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Nguyễn Hưng Phát 16/11/2017 at 12:56
We have:218=4x⇔218−4x=0⇔(22)9−4x=0⇔49−4x=0⇔4x(49−x−1)=0.Because 4x>0 so 49-x=1⇒9−x=0⇒x=9
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\(2^{18}=\left(2^2\right)^9=4^9\). So, x = 9