B

9000021803

Level: 
B
Solve the following inequality. \[ (3x - 1)(2 - 4x) < 0 \]
\(x\in \left (-\infty ; \frac{1} {3}\right )\cup \left (\frac{1} {2};\infty \right )\)
\(x\in \left (\frac{1} {3}; \frac{1} {2}\right )\)
\(x\in \left (-\infty ; \frac{1} {2}\right )\)
\(x\in \left (\frac{1} {3};\infty \right )\)

9000019907

Level: 
B
The augmented matrix of a system of three equations with three unknowns is row equivalent with the following matrix \(A'\). Find the solution of the system. \[ A' = \left(\begin{array}{ccc|c} 1 & 2 & 4 & 0\\ 0 & 2 & 7 & 7\\ 0 & 0 & 7 & 35 \end{array}\right) \]
\([8;-14;5]\)
\([-62;21;5]\)
\([8;14;-5]\)
\([-22;-21;5]\)

9000019908

Level: 
B
The augmented matrix of a system of three equations with three unknowns is row equivalent with the following matrix \(A'\). Find the solution of the system. \[ A' = \left(\begin{array}{ccc|c} -1 & 0 & 1 &-1\\ 0 & 7 & 2 & -1\\ 0 & 0 & 30 & 6 \end{array}\right) \]
\(\left [\frac{6} {5};-\frac{1} {5}; \frac{1} {5}\right ]_{}\)
\(\left [\frac{1} {5};-\frac{1} {5}; \frac{6} {5}\right ]\)
\(\left [\frac{1} {5};-\frac{6} {5};-\frac{1} {5}\right ]\)
\(\left [-\frac{6} {5}; \frac{1} {5}; \frac{1} {5}\right ]\)

9000014206

Level: 
B
Find the domain \(\mathrm{Dom}(f)\) and range \(\mathop{\mathrm{Ran}}(f)\) of the function \(f(x) = \frac{2+x} {x+4}\).
\begin{align*} \mathrm{Dom}(f) &= (-\infty ;-4)\cup (-4;\infty ),\\ \mathop{\mathrm{Ran}}(f) &= (-\infty ;1)\cup (1;\infty ) \end{align*}
\begin{align*} \mathrm{Dom}(f) &= (-\infty ;4)\cup (4;\infty ), \\ \mathop{\mathrm{Ran}}(f) &= (-\infty ;1)\cup (1;\infty ) \end{align*}
\begin{align*} \mathrm{Dom}(f) &= (-\infty ;2)\cup (2;\infty ),\\ \mathop{\mathrm{Ran}}(f) &= (-\infty ;4)\cup (4;\infty ) \end{align*}
\begin{align*} \mathrm{Dom}(f) &= (-\infty ;4)\cup (4;\infty ), \\ \mathop{\mathrm{Ran}}(f) &= (-\infty ;2)\cup (2;\infty ) \end{align*}

9000019909

Level: 
B
The augmented matrix of a system of three equations with three unknowns is the following matrix \(M'\). Identify the matrix which is row equivalent to \(M'\). \[ M' = \left(\begin{array}{ccc|c} 1 & 2 & 4 & 14\\ -1 & 0 & 3 & 7\\ 3 & 1 & -2 & 42 \end{array}\right) \]
\(\left(\begin{array}{ccc|c} 1 & 2 & 4 & 14\\ 0 & 2 & 7 & 21\\ 0 & 0 & 7 & 105 \end{array}\right)\)
\(\left(\begin{array}{ccc|c} 1 & 2 & 4 & 14\\ 0 & 2 & 7 & 21\\ 0 & 0 & -8 & 70 \end{array}\right)\)
\(\left(\begin{array}{ccc|c} 1 & 2 & 4 & 14\\ 0 & 2 & 7 & 21\\ 0 & 0 & -29 & -147 \end{array}\right)\)
\(\left(\begin{array}{ccc|c} 1 & 2 & 4 & 14\\ 0 & 2 & 1 & 7\\ 0 & 0 & -23 & 35 \end{array}\right)\)