Giải thích các bước giải:
Ta có:
\(\begin{array}{l}
a,\\
104 - \left( {48:x + 1916} \right):12:4 = 64\\
\Leftrightarrow \left( {48:x + 1916} \right):12:4 = 104 - 64\\
\Leftrightarrow \left( {48:x + 1916} \right):12:4 = 40\\
\Leftrightarrow \left( {48:x + 1916} \right):12 = 40.4\\
\Leftrightarrow \left( {48:x + 1916} \right):12 = 160\\
\Leftrightarrow \left( {48:x + 1916} \right) = 160.12\\
\Leftrightarrow 48:x + 1916 = 1920\\
\Leftrightarrow 48:x = 1920 - 1916\\
\Leftrightarrow 48:x = 4\\
\Leftrightarrow x = 48:4\\
\Leftrightarrow x = 12\\
b,\\
x.\left( {{2^3} + {5^2}} \right) = 2.\left( {{5^2} + {2^3}} \right) - 33\\
\Leftrightarrow x.\left( {8 + 25} \right) = 2.\left( {25 + 8} \right) - 33\\
\Leftrightarrow x.33 = 2.33 - 33\\
\Leftrightarrow x.33 = 33\\
\Leftrightarrow x = 33:33\\
\Leftrightarrow x = 1\\
c,\\
{2^2}.3.\left( {x + 5} \right) - {6^2} = \left( {{2^3} + {2^2}} \right){.2^2}\\
\Leftrightarrow {2^2}.3.\left( {x + 5} \right) - {\left( {2.3} \right)^2} = \left( {8 + 4} \right){.2^2}\\
\Leftrightarrow {2^2}.3.\left( {x + 5} \right) - {2^2}{.3^2} = {12.2^2}\\
\Leftrightarrow 3.\left( {x + 5} \right) - {3^2} = 12\\
\Leftrightarrow 3.\left( {x + 5} \right) - 9 = 12\\
\Leftrightarrow 3.\left( {x + 5} \right) = 12 + 9\\
\Leftrightarrow 3.\left( {x + 5} \right) = 21\\
\Leftrightarrow x + 5 = 21:3\\
\Leftrightarrow x + 5 = 7\\
\Leftrightarrow x = 7 - 5\\
\Leftrightarrow x = 2\\
d,\\
\left( {{3^2} - 2} \right).\left( {x - 12} \right) + 35 = {5^2} + 279:{3^2}\\
\Leftrightarrow \left( {9 - 2} \right).\left( {x - 12} \right) + 35 = 25 + 279:9\\
\Leftrightarrow 7.\left( {x - 12} \right) + 35 = 25 + 31\\
\Leftrightarrow 7.\left( {x - 12} \right) + 35 = 56\\
\Leftrightarrow 7.\left( {x - 12} \right) = 56 - 35\\
\Leftrightarrow 7.\left( {x - 12} \right) = 21\\
\Leftrightarrow x - 12 = 21:7\\
\Leftrightarrow x - 12 = 3\\
\Leftrightarrow x = 12 + 3\\
\Leftrightarrow x = 15\\
e,\\
{2^3}.x + {2009^0}.x = 996 - 18:3\\
\Leftrightarrow 8.x + 1.x = 996 - 6\\
\Leftrightarrow x.\left( {8 + 1} \right) = 990\\
\Leftrightarrow x.9 = 990\\
\Leftrightarrow x = 990:9\\
\Leftrightarrow x = 110\\
f,\\
707:\left[ {\left( {{2^x} - 5} \right) + 74} \right] = {4^2} - {3^2}\\
\Leftrightarrow 707:\left[ {\left( {{2^x} - 5} \right) + 74} \right] = 16 - 9\\
\Leftrightarrow 707:\left[ {\left( {{2^x} - 5} \right) + 74} \right] = 7\\
\Leftrightarrow \left( {{2^x} - 5} \right) + 74 = 707:7\\
\Leftrightarrow \left( {{2^x} - 5} \right) + 74 = 101\\
\Leftrightarrow {2^x} - 5 = 101 - 74\\
\Leftrightarrow {2^x} - 5 = 27\\
\Leftrightarrow {2^x} = 27 + 5\\
\Leftrightarrow {2^x} = 32\\
\Leftrightarrow {2^x} = {2^5}\\
\Leftrightarrow x = 5
\end{array}\)
