Answer
$-3p^{-7/4} \left( p+10 \right)$
Work Step by Step
Factoring out the given factor, $
-3p^{-7/4}
,$ then the given expression, $
-3p^{-3/4}-30p^{-7/4}
,$ is equivalent to
\begin{array}{l}\require{cancel}
-3p^{-7/4} \left( \dfrac{-3p^{-3/4}}{-3p^{-7/4}}-\dfrac{30p^{-7/4}}{-3p^{-7/4}} \right)
\\\\=
-3p^{-7/4} \left( p^{-\frac{3}{4}-\left(-\frac{7}{4}\right)}+10p^{-\frac{7}{4}-\left(-\frac{7}{4}\right)} \right)
\\\\=
-3p^{-7/4} \left( p^{-\frac{3}{4}+\frac{7}{4}}+10p^{-\frac{7}{4}+\frac{7}{4}} \right)
\\\\=
-3p^{-7/4} \left( p^{\frac{4}{4}}+10p^{0} \right)
\\\\=
-3p^{-7/4} \left( p^{1}+10(1) \right)
\\\\=
-3p^{-7/4} \left( p+10 \right)
.\end{array}