B

9000022906

Level: 
B
Find the values of a real parameter \(t\) which ensure that the following system has a unique solution \([a,b]\) such that both \(a\) and \(b\) are positive real numbers. \[ \begin{alignedat}{80} a & - &tb & = - &2 & & & & & & \\a & + 2 &tb & = &0 & & & & & & \\\end{alignedat}\]
\(t\in \emptyset \)
\(t\in \mathbb{R}^{+}\)
\(t\in \mathbb{R}^{-}\)
\(t = 0\)
\(t\in \mathbb{R}\)

9000022804

Level: 
B
Establish the values of the real parameter \(t\) which ensure that the following expression is nonpositive. \[ \frac{2} {2t^{2} + t - 1} \]
\(\left (-1; \frac{1} {2}\right )\)
\(\left [ -\frac{1} {2};1\right ] \)
\(\left [ -1; \frac{1} {2}\right ] \)
\(\left (-\frac{1} {2};1\right )\)

9000022306

Level: 
B
Using the graph of the function \(f(x)= -x^{2} - 2x + 8\) solve the following inequality. \[ -x^{2} - 2x + 8\leq 5 \]
\(\left (-\infty ;-3\right ] \cup \left [ 1;\infty \right )\)
\(\left (-\infty ;-4\right ] \cup \left [ 2;\infty \right )\)
\(\left [ -3;1\right ] \)
\(\left [ -4;2\right ] \)

9000022308

Level: 
B
Using graphs of the functions \(f(x)= -2x^{2} + 3x + 4\) and \(g(x) = x\) solve the following quadratic inequality. \[ -2x^{2} + 3x + 4\geq x \]
\(\left [ -1;2\right ] \)
\(\{ - 1;2\}\)
\(\left (-1;2\right )\)
\(\left (-\infty ;-1\right )\cup \left (2;\infty \right )\)

9000022309

Level: 
B
Using graphs of the functions \(f(x) = x^{2} + x - 1\) and \(g(x) = -\frac{1} {2}x\) solve the following quadratic inequality. \[ x^{2} + x - 1 > -\frac{1} {2}x \]
\(\left (-\infty ;-2\right )\cup \left (\frac{1} {2};\infty \right )\)
\(\left (-2; \frac{1} {2}\right )\)
\(\left [ -2; \frac{1} {2}\right ] \)
\(\left (-\infty ;-2\right ] \cup \left [ \frac{1} {2};\infty \right )\)