Answer:
[tex]n = 3[/tex]
Step-by-step explanation:
[tex] {p}^{3} {q}^{2} ( \frac{ {p}^{4} {q}^{n} {r}^{3} }{ {r}^{ - 4} } ) = {p}^{7 } {q}^{5} {r}^{7} \\ {p}^{7} {q}^{2 + n} {r}^{7} = {p}^{7} {q}^{5} {r}^{7} \\ {q}^{2 + n} = {q}^{5} \\ 2 + n = 5 \\ n = 5 - 2 \\ n = 3 [/tex]
