\(\left(2x^2-2x-1\right)\left(5x-5\right)\)
\(\Leftrightarrow2x^2\left(5x-5\right)-2x\left(5x-5\right)-\left(5x-5\right)\)
\(\Leftrightarrow10x^3-10x^2-2x\left(5x-5\right)-\left(5x-5\right)\)
\(\Leftrightarrow10x^3-10x^2-2x\left(5x-5\right)-\left(5x-5\right)\)
\(\Leftrightarrow10x^3-10x^2-\left(10x^2-10x\right)-\left(5x-5\right)\)
\(\Leftrightarrow10x^3-10x^2-10x^2+10x-5x+5\)
\(\Leftrightarrow10x^3-20x^2+5x+5\)