Đáp án:
Giải thích các bước giải:
\(\begin{array}{l}
B1:\\
a.2x + 6 = 2x - 8 + 14\\
\to 14 = 14\left( {ld} \right)
\end{array}\)
⇒ Vô số nghiệm
\(\begin{array}{l}
b.2x - 1 + 4 - 2x = 1\\
\to 3 = 1 ( vô lí )
\end{array}\)
⇒ Vô nghiệm
\(\begin{array}{l}
c.10x - 4 = 15 - 9x\\
\to 19x = 19\\
\to x = 1\\
d.2x + \frac{6}{5} = 5 - \frac{{13 + 5x}}{5}\\
\to 10x + 6 = 25 - 13 - 5x\\
\to 15x = 6\\
\to x = \frac{2}{5}\\
B2:\\
a.\left( {x - 3} \right)\left( {2x - 5} \right) = 0\\
\to \left[ \begin{array}{l}
x = 3\\
x = \frac{5}{2}
\end{array} \right.\\
b.\left( {x - 1} \right)\left( {{x^2} + x + 1} \right) - \left( {x - 1} \right)\left( {{x^2} - 3x + 5} \right) = 0\\
\to \left( {x - 1} \right)\left( {4x - 4} \right) = 0\\
\to 4{\left( {x - 1} \right)^2} = 0\\
\to x = 1\\
c.\left[ \begin{array}{l}
{x^2} + 1 = 0\left( {voli} \right)\\
4{x^2} - 4x + 1 = 0
\end{array} \right.\\
\to {\left( {2x - 1} \right)^2} = 0\\
\to x = \frac{1}{2}\\
d.\left( {x + 1} \right)\left( {3x - 1} \right) = 0\\
\to \left[ \begin{array}{l}
x = - 1\\
x = \frac{1}{3}
\end{array} \right.
\end{array}\)
