Giải thích các bước giải:
\(\begin{array}{l}
a.\left( {x + 3} \right).\left( {x - 2} \right) = 0\\
\to \left[ \begin{array}{l}
x = - 3\\
x = 2
\end{array} \right.\\
b.4.\left( {x - 5} \right) - 3.\left( {x + 7} \right) = - 19\\
\to 4x - 20 - 3x - 21 + 19 = 0\\
\to x = 22\\
c.2.\left( {x - 5} \right) - 3.\left( {x + 7} \right) = 14\\
\to 2x - 10 - 3x - 21 = 14\\
\to - x = 45 \to x = - 45\\
d.3.\left( {x - 4} \right) - \left( {8 - x} \right) = 12\\
\to 3x - 12 - 8 + x = 12\\
\to 4x = 32\\
\to x = 8
\end{array}\)
