2x squared minus 50 factored completely
\(2{ x }^{ 2 }-50\\ \\ =2\left( { x }^{ 2 }-25 \right) \\ \\ =2\left( { x }^{ 2 }-{ 5 }^{ 2 } \right) \\ \\ =2\left( x+5 \right) \left( x-5 \right) \\\)