Giải thích các bước giải:
Ta có:
\(\begin{array}{l}
j,\\
515:\left( {x + 35} \right) = 5\\
\Leftrightarrow x + 35 = 515:5\\
\Leftrightarrow x + 35 = 103\\
\Leftrightarrow x = 103 - 35\\
\Leftrightarrow x = 68\\
k,\\
740:\left( {x + 10} \right) = {10^2} - 2.13\\
\Leftrightarrow 740:\left( {x + 10} \right) = 100 - 26\\
\Leftrightarrow 740:\left( {x + 10} \right) = 74\\
\Leftrightarrow x + 10 = 740:74\\
\Leftrightarrow x + 10 = 10\\
\Leftrightarrow x = 0\\
l,\\
20 - \left[ {7\left( {x - 3} \right) + 4} \right] = 2\\
\Leftrightarrow 7\left( {x - 3} \right) + 4 = 20 - 2\\
\Leftrightarrow 7.\left( {x - 3} \right) + 4 = 18\\
\Leftrightarrow 7.\left( {x - 3} \right) = 18 - 4\\
\Leftrightarrow 7\left( {x - 3} \right) = 14\\
\Leftrightarrow x - 3 = 14:7\\
\Leftrightarrow x - 3 = 2\\
\Leftrightarrow x = 5\\
m,\\
{\left( {2x + 1} \right)^3} = 125\\
\Leftrightarrow {\left( {2x + 1} \right)^3} = {5^3}\\
\Leftrightarrow 2x + 1 = 5\\
\Leftrightarrow 2x = 5 - 1\\
\Leftrightarrow 2x = 4\\
\Leftrightarrow x = 4:2\\
\Leftrightarrow x = 2\\
n,\\
{2^x}.4 = 128\\
\Leftrightarrow {2^x} = 128:4\\
\Leftrightarrow {2^x} = 32\\
\Leftrightarrow {2^x} = {2^5}\\
\Leftrightarrow x = 5\\
l,\\
{\left( {x - 5} \right)^4} = {\left( {x - 5} \right)^6}\\
\Leftrightarrow {\left( {x - 5} \right)^4} - {\left( {x - 5} \right)^6} = 0\\
\Leftrightarrow {\left( {x - 5} \right)^4}.\left[ {1 - {{\left( {x - 5} \right)}^2}} \right] = 0\\
\Leftrightarrow \left[ \begin{array}{l}
{\left( {x - 5} \right)^4} = 0\\
1 - {\left( {x - 5} \right)^2} = 0
\end{array} \right. \Leftrightarrow \left[ \begin{array}{l}
x - 5 = 0\\
{\left( {x - 5} \right)^2} = 1
\end{array} \right. \Leftrightarrow \left[ \begin{array}{l}
x = 5\\
x - 5 = 1\\
x - 5 = - 1
\end{array} \right. \Leftrightarrow \left[ \begin{array}{l}
x = 5\\
x = 6\\
x = 4
\end{array} \right.\\
p,\\
{2^{x + 2}} - {2^x} = 96\\
\Leftrightarrow {2^x}{.2^2} - {2^x} = 96\\
\Leftrightarrow {2^x}.\left( {{2^2} - 1} \right) = 96\\
\Leftrightarrow {2^x}.3 = 96\\
\Leftrightarrow {2^x} = 96:3\\
\Leftrightarrow {2^x} = 32\\
\Leftrightarrow {2^x} = {2^5}\\
\Leftrightarrow x = 5\\
q,\\
{x^{10}} = {1^x}\\
\Leftrightarrow {x^{10}} = 1\\
\Leftrightarrow x = \pm 1
\end{array}\)
