Answer:
[tex] - {5c}^{4} \times ( { - c}^{8} ) \\ \\ = 5 \{( {c}^{4} ) \times (c {}^{8} ) \} \\ \\ [/tex]
from law of indices:
[tex] {a}^{n} \times {a}^{m} = {a}^{(n + m)} [/tex]
therefore:
[tex] = 5 \{ {c}^{(4 + 8)} \} \\ \\ { \boxed{ = 5 {c}^{12} }}[/tex]
