Đáp án:
\(\begin{array}{l}
a.x = 2\\
b.\left[ \begin{array}{l}
x = - 3\\
x = 2
\end{array} \right.\\
c.x > 2\\
d.x < \frac{7}{5}
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
a.{x^2} - 2x - 3 - {x^2} - 1 = 0\\
\to - 2x - 4 = 0\\
\to 2x = 4\\
\to x = 2\\
b.\left( {x - 3} \right)\left( {x + 3} \right) + \left( {x - 1} \right)\left( {x + 3} \right) = 0\\
\to \left( {x + 3} \right)\left( {x - 3 + x - 1} \right) = 0\\
\to \left[ \begin{array}{l}
x + 3 = 0\\
2x - 4 = 0
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = - 3\\
x = 2
\end{array} \right.\\
c.2x - 3 > 1\\
\to 2x > 4\\
\to x > 2\\
d.\frac{{3\left( {3x - 2} \right) + 1 - 2\left( {2x + 1} \right)}}{6} < 0\\
\to 9x - 6 + 1 - 4x - 2 < 0\\
\to 5x - 7 < 0\\
\to x < \frac{7}{5}
\end{array}\)
