Đáp án:
C3:
c) x=4
Giải thích các bước giải:
\(\begin{array}{l}
C3:\\
1)DK:\dfrac{1}{3} \ge x\\
2\sqrt {1 - 3x} + 3\sqrt {1 - 3x} = 10\\
\to 5\sqrt {1 - 3x} = 10\\
\to \sqrt {1 - 3x} = 2\\
\to 1 - 3x = 4\\
\to 3x = - 3\\
\to x = - 1\left( {TM} \right)\\
2)DK:x \ge 0\\
2x - 3\sqrt x + 2\sqrt x - 3 - 2x = - 4\\
\to - \sqrt x = - 1\\
\to \sqrt x = 1\\
\to x = 1\left( {TM} \right)\\
3)DK:x \ge 1\\
\sqrt {2x + 1} = x - 1\\
\to 2x + 1 = {x^2} - 2x + 1\\
\to {x^2} - 4x = 0\\
\to x\left( {x - 4} \right) = 0\\
\to \left[ \begin{array}{l}
x = 0\left( l \right)\\
x = 4\left( {TM} \right)
\end{array} \right.
\end{array}\)
