$$\left. \begin{array} { l } { 2 x ^ { 2 } + x - 3 } \\ { 6 x ^ { 2 } + 11 x - 2 } \\ { 2 a ^ { 2 } - 5 a - 12 } \\ { 8 x ^ { 2 } - 22 x - 21 } \end{array} \right.$$
$\left(x-1\right)\left(2x+3\right),\ \left(6x-1\right)\left(x+2\right),\ \left(a-4\right)\left(2a+3\right),\ \left(2x-7\right)\left(4x+3\right)$
