91Ó°ÊÓ

For Problems \(13-26\), compute \(A B\) and \(B A\). $$ A=\left[\begin{array}{ll} 2 & -4 \\ 1 & -2 \end{array}\right], \quad B=\left[\begin{array}{rr} 1 & -2 \\ -3 & 6 \end{array}\right] $$

For Problems \(1-18\), find the multiplicative inverse (if one exists) of each matrix. $$ \left[\begin{array}{rr} 1 & 1 \\ 1 & -1 \end{array}\right] $$

For Problems \(9-20\), find \(A B\) and \(B A\), whenever they exist. $$ A=\left[\begin{array}{r} 2 \\ -7 \end{array}\right], \quad B=\left[\begin{array}{rr} 3 & -2 \\ 1 & 0 \\ -1 & 4 \end{array}\right] $$

For Problems \(9-20\), find \(A B\) and \(B A\), whenever they exist. $$ A=\left[\begin{array}{rrrr} 3 & -2 & 2 & -4 \\ 1 & 0 & -1 & 2 \end{array}\right], \quad B=\left[\begin{array}{rrr} 3 & -2 & 1 \\ -3 & 1 & 4 \\ 5 & 2 & 0 \\ -4 & -1 & -2 \end{array}\right] $$

For Problems \(1-24\), indicate the solution set for each system of inequalities by graphing the system and shading the appropriate region. $$ \left(\begin{array}{l} x \leq 3 \\ y \leq-1 \end{array}\right) $$

For Problems \(1-18\), find the multiplicative inverse (if one exists) of each matrix. $$ \left[\begin{array}{rr} 1 & -1 \\ 1 & 1 \end{array}\right] $$

For Problems \(13-26\), compute \(A B\) and \(B A\). $$ A=\left[\begin{array}{ll} 1 & 2 \\ 1 & 2 \end{array}\right], \quad B=\left[\begin{array}{rr} 2 & 2 \\ -1 & -1 \end{array}\right] $$

For Problems \(1-24\), indicate the solution set for each system of inequalities by graphing the system and shading the appropriate region. $$ \left(\begin{array}{l} y>-2 \\ x>1 \end{array}\right) $$

For Problems \(9-20\), find \(A B\) and \(B A\), whenever they exist. $$ A=\left[\begin{array}{r} 3 \\ -4 \\ 2 \end{array}\right], \quad B=\left[\begin{array}{ll} 3 & -4 \end{array}\right] $$

For Problems \(13-26\), compute \(A B\) and \(B A\). $$ A=\left[\begin{array}{ll} -3 & -2 \\ -4 & -1 \end{array}\right], \quad B=\left[\begin{array}{rr} 2 & -1 \\ 4 & 5 \end{array}\right] $$