Разделите многочлен \(\displaystyle z^{\,2}+13z+30\) на многочлен \(\displaystyle z+3\) в столбик:

\(\displaystyle -\)	\(\displaystyle \phantom{\,\,} z^{\,2}+13z+30\)				\(\displaystyle z+3\)
	[ ]				[ ]
	\(\displaystyle \phantom{ x^{\,2}+} -\)	[ ]
		[ ]
		\(\displaystyle 0\phantom{ xx}\)

и запишите разложение:

\(\displaystyle z^{\,2}+13z+30=(z+3)\cdot \big(\)[ ]\(\displaystyle \big){\small . }\)