\[- 10^{4} + ( - 5)^{3} = - 10000 - 5^{3} =\]
\[= - 10000 - 5^{2} \cdot 5 =\]
\[= - 10000 - 25 \cdot 5 =\]
\[= - 10000 - 125 = - 10\ 125.\]