Systems of Linear Equations and Inequalities

9000022904

Level: 
B
Find the values of a real parameter \(t\) which ensure that the following system has a unique solution. \[ \begin{alignedat}{80} 2x & + &y & + &t & = - &2 & & & & & & & & \\ - 4x & - 2 &y & + &1 & = &0 & & & & & & & & \\\end{alignedat}\]
\(t\in \emptyset \)
\(t\in \mathbb{R}\)
\(t = 3\)
\(t = 1\)
\(t\in \mathbb{R}\setminus \{3\}\)

9000022905

Level: 
B
Find the values of a real parameter \(t\) which ensure that the following system has a unique solution. \[ \begin{alignedat}{80} tx & + &y & + &3 & = 0 & & & & & & \\4x & - 2 &y & + &1 & = 0 & & & & & & \\\end{alignedat}\]
\(t\in \mathbb{R}\setminus \{ - 2\}\)
\(t\in \mathbb{R}\)
\(t = -2\)
\(t\in \emptyset \)

9000021801

Level: 
C
Solve the following system of inequalities. \[\begin{aligned} \frac{1} {3}(2x + 5) &\geq 0.5\left (\frac{2 + 3x} {2} + 2\right ) & & \\0.2(3 - 2x) &\leq \frac{1} {3}\left (\frac{4 - 2x} {5} + 2\right ) & & \end{aligned}\]
\(x\in \left [ -\frac{5} {4};2\right ] \)
\(x\in [ 2;\infty )\)
\(x\in \left (-\infty ;-\frac{5} {4}\right ] \)
\(x\in \emptyset \)