Giải thích các bước giải:

Ta có:

\(\begin{array}{l}
2,\\
a,\\
14 + 6:2.3 = 14 + 3.3 = 14 + 9 = 23\\
c,\\
{4^2}.47 - {4^2}.38 + {4^2} = {4^2}.\left( {47 - 38 + 1} \right)\\
 = {4^2}.10 = 16.10 = 160\\
d,\\
24.36 + 3.35.8 + 2.12.39\\
 = 24.36 + \left( {3.8} \right).35 + \left( {2.12} \right).39\\
 = 24.36 + 24.35 + 24.39\\
 = 24.\left( {36 + 35 + 39} \right)\\
 = 24.110 = 24.11.10 = 264.10 = 2640\\
e,\\
46 - \left[ {45 - {{\left( {37 - 34} \right)}^2}} \right]\\
 = 46 - \left[ {45 - {3^2}} \right]\\
 = 46 - \left( {45 - 9} \right)\\
 = 46 - 45 + 9\\
 = 1 + 9 = 10\\
f,\\
{6^{10}}:{6^8} - {202^0} + {1^{2020}}\\
 = {6^{10 - 8}} - 1 + 1\\
 = {6^2} = 36\\
3,\\
a,\\
17 + x = {2^3}{.3^2}\\
 \Leftrightarrow 17 + x = 8.9\\
 \Leftrightarrow 17 + x = 72\\
 \Leftrightarrow x = 72 - 17\\
 \Leftrightarrow x = 55\\
b,\\
2x + 19 = 39\\
 \Leftrightarrow 2x = 39 - 19\\
 \Leftrightarrow 2x = 20\\
 \Leftrightarrow x = 20:2\\
 \Leftrightarrow x = 10\\
c,\\
24 - \left( {x - 12} \right) = 20\\
 \Leftrightarrow x - 12 = 24 - 20\\
 \Leftrightarrow x - 12 = 4\\
 \Leftrightarrow x = 4 + 12\\
 \Leftrightarrow x = 16\\
d,\\
18 + 2.\left( {x + 1} \right) = 30\\
 \Leftrightarrow 2.\left( {x + 1} \right) = 30 - 18\\
 \Leftrightarrow 2.\left( {x + 1} \right) = 12\\
 \Leftrightarrow x + 1 = 12:2\\
 \Leftrightarrow x + 1 = 6\\
 \Leftrightarrow x = 6 - 1\\
 \Leftrightarrow x = 5\\
e,\\
2.{x^3} = 16\\
 \Leftrightarrow {x^3} = 16:2\\
 \Leftrightarrow {x^3} = 8\\
 \Leftrightarrow {x^3} = {2^3}\\
 \Leftrightarrow x = 2
\end{array}\)