B

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 \(M'\). \[ M' = \left(\begin{array}{ccc|c} 1 & 2 & 4 & 14\\ -1 & 0 & 3 & 7\\ 3 & 1 & -2 & 42 \end{array}\right) \]
\(\left(\begin{array}{ccc|c} 1 & 2 & 4 & 14\\ 0 & 2 & 7 & 21\\ 0 & 0 & 7 & 105 \end{array}\right)\)
\(\left(\begin{array}{ccc|c} 1 & 2 & 4 & 14\\ 0 & 2 & 7 & 21\\ 0 & 0 & -8 & 70 \end{array}\right)\)
\(\left(\begin{array}{ccc|c} 1 & 2 & 4 & 14\\ 0 & 2 & 7 & 21\\ 0 & 0 & -29 & -147 \end{array}\right)\)
\(\left(\begin{array}{ccc|c} 1 & 2 & 4 & 14\\ 0 & 2 & 1 & 7\\ 0 & 0 & -23 & 35 \end{array}\right)\)

9000019910

Level: 
B
The augmented matrix of a system of three equations with three unknowns is row equivalent to the following matrix \(A'\). Find the solution of the system. \[ A' = \left(\begin{array}{ccc|c} -1 & -6 & 1 &-20\\ 0 & 5 & 4 & -12\\ 0 & 0 & 0 & -8 \end{array}\right) \]
no solution
\(\left [-\frac{172} {5} ;-\frac{12} {5} ;0\right ]\)
\([-12t;4t;-8t],\ t\in \mathbb{R}\)
\(\left [-12;4;-8\right ]\)

9000018101

Level: 
B
Solve the following inequality: \[ 7 -\left (4x - 1\right ) < 3\left (x + 4\right ) \]
\(x\in \left (-\frac{4} {7};\infty \right )\)
\(x\in \left (-\infty ; \frac{4} {7}\right )\)
\(x\in \left (\frac{4} {7};\infty \right )\)
\(x\in \left (-\infty ;-\frac{4} {7}\right )\)