Giải thích các bước giải:
$\begin{array}{l}
h)3{x^3}\left( {2y - 3z} \right) - 15x\left( {2y - 3z} \right)\\
= \left( {2y - 3z} \right)\left( {3{x^3} - 15x} \right)\\
= \left( {2y - 3z} \right)3x\left( {{x^2} - 5} \right)\\
k)3x\left( {z + 2} \right) + 5\left( { - x - 2} \right)\\
= 3xz + 6x - 5x - 10\\
= 3xz + x - 10\\
l)18{x^2}\left( {3 + x} \right) + 3\left( {x + 3} \right)\\
= 3\left( {x + 3} \right)\left( {6{x^2} + 1} \right)\\
m)14{x^2}y - 21x{y^2} + 28{x^2}{y^2}\\
= 7xy\left( {2x - 3y + 4xy} \right)\\
n)10x\left( {x - y} \right) - 8y\left( {y - x} \right)\\
= 2\left( {x - y} \right)\left( {5x + 4y} \right)\\
g)3{x^2}{y^2}\left( {a - b + c} \right) + 2xy\left( {b - a - c} \right)\\
= 3{x^2}{y^2} - 2xy\left( {a - b + c} \right)\\
= xy\left( {a - b + c} \right)\left( {3xy - 2} \right)
\end{array}$
