Giải thích các bước giải:
Ta có:
\(\begin{array}{l}
1.27\\
a,\\
{\left( {2x + 1} \right)^3} = 125\\
\Leftrightarrow {\left( {2x + 1} \right)^3} = {5^3}\\
\Leftrightarrow 2x + 1 = 5\\
\Leftrightarrow 2x = 4\\
\Leftrightarrow x = 2\\
b,\\
{\left( {4x - 1} \right)^2} = 25.9\\
\Leftrightarrow {\left( {4x - 1} \right)^2} = {5^2}{.3^2}\\
\Leftrightarrow {\left( {4x - 1} \right)^2} = {\left( {5.3} \right)^2}\\
\Leftrightarrow 4x - 1 = 15\\
\Leftrightarrow 4x = 16\\
\Leftrightarrow x = 4\\
1.28\\
a,\\
{2^x} + {2^{x + 3}} = 144\\
\Leftrightarrow {2^x} + {2^x}{.2^3} = 144\\
\Leftrightarrow {2^x}.\left( {1 + {2^3}} \right) = 144\\
\Leftrightarrow {2^x}.9 = 144\\
\Leftrightarrow {2^x} = 16\\
\Leftrightarrow {2^x} = {2^4}\\
\Leftrightarrow x = 4\\
b,\\
{3^{2x + 2}} = {9^{x + 3}}\\
\Leftrightarrow {3^{2x + 2}} = {\left( {{3^2}} \right)^{x + 3}}\\
\Leftrightarrow {3^{2x + 2}} = {3^{2x + 6}}\\
\Leftrightarrow 2x + 2 = 2x + 6\,\,\,\,\,\,\,\,\,\,\,\left( L \right)\\
1.29\\
a,\\
{\left( {x - 5} \right)^4} = {\left( {x - 5} \right)^6}\\
\Leftrightarrow \left[ \begin{array}{l}
x - 5 = 0\\
x - 5 = 1
\end{array} \right. \Leftrightarrow \left[ \begin{array}{l}
x = 5\\
x = 6
\end{array} \right.\\
b,\\
{x^{15}} = {x^2} \Leftrightarrow \left[ \begin{array}{l}
x = 0\\
x = 1
\end{array} \right.
\end{array}\)
