## College Algebra (6th Edition)

$X=\left[\begin{array}{ll} -2/3 & 2\\ -2/3 & 3\\ -2/3 & -4/3 \end{array}\right]$
Use the Properties of Matrix Addition (page 614) and the Properties of Scalar Multiplication (page 616) $3X+A=B$ ... Subtract A from both sides $3X=B-A$ ... Multiply both sides with a scalar, $\displaystyle \frac{1}{3}$ $X=\displaystyle \frac{1}{3}(B-A)$ $X=\displaystyle \frac{1}{3}\left[\begin{array}{ll} -5-(-3) & -1-(-7)\\ 0-2 & 0-(-9)\\ 3-5 & -4-0 \end{array}\right]=\displaystyle \frac{1}{3}\left[\begin{array}{ll} -2 & 6\\ -2 & 9\\ -2 & -4 \end{array}\right]$ $X=\left[\begin{array}{ll} -2/3 & 2\\ -2/3 & 3\\ -2/3 & -4/3 \end{array}\right]$