1. Tính theo cách hợp lí:
\(2016.5^{2017}.\left(30.5^{2015}-5^{2016}\right)\)
\(=2016.5^{2017}.5^{2015}.\left(30-5\right)\)
\(=2016.5^{4032}.25\)
\(=2016.5^{4032}.5^2\)
\(=2016.5^{4034}\)
2. Tìm x:
\(4^{x+1}+4^0=65\)
\(\Leftrightarrow4^{x+1}+1=65\)
\(\Leftrightarrow4^{x+1}=65-1\)
\(\Leftrightarrow\left(2^2\right)^{x+1}=64\)
\(\Leftrightarrow2^{2x+2}=2^6\)
\(\Rightarrow2x+2=6\)
\(\Rightarrow2x=4\)
\(\Rightarrow x=2.\)
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