## Elementary Linear Algebra 7th Edition

Factor $4$ out of the second column and factor $3$ out of the third column.
$$\left|\begin{array}{rrr}{1} & {8} & {-3} \\ {3} & {-12} & {6} \\ {7} & {4} & {9}\end{array}\right|=12\left|\begin{array}{rrr}{1} & {2} & {-1} \\ {3} & {-3} & {2} \\ {7} & {1} & {3}\end{array}\right|$$ Factor $4$ out of the second column and factor $3$ out of the third column.