1. \(4x^2-8x\)
\(\Leftrightarrow4x.\left(x-2\right)\)
2. \(x^2-16\)
\(\Leftrightarrow\left(x-4\right).\left(x+4\right)\)
3. \(25-\left(x+1\right)^2\)
\(\Leftrightarrow\left(5-x-1\right).\left(5+x+1\right)\)
\(\Leftrightarrow\left(4-x\right).\left(6+x\right)\)
4. \(\left(y-2\right)^2-9\)
\(\Leftrightarrow\left(y-2-3\right).\left(y-2+3\right)\)
\(\Leftrightarrow\left(y-5\right).\left(y+1\right)\)
5. \(x^3-64\)
\(\Leftrightarrow\left(x-4\right).\left(x^2+4x+16\right)\)
6. \(1818+27y^2\)
\(\Leftrightarrow9.\left(202+3y^2\right)\)
7. \(x^2-10+25\)
\(\Leftrightarrow\left(x-5\right)^2\)
8. \(16+8x+x^2\)
\(\Leftrightarrow\left(4+x\right)^2\)
9. \(7x^2-7xy-5x+5y\)
\(\Leftrightarrow7x.\left(x-y\right)-5.\left(x-y\right)\)
\(\Leftrightarrow\left(7x-5\right).\left(x-y\right)\)
10. \(x^3-3x^2+3x-9\)
\(\Leftrightarrow x^2.\left(x-3\right)+3.\left(x-3\right)\)
\(\Leftrightarrow\left(x^2+3\right).\left(x-3\right)\)