g) \(x^2-2xy+y^2-9\)
\(=\left(x-y\right)^2-3^2\)
\(=\left(x-y-3\right)\left(x-y+3\right)\)
h) \(5x^4-20x^2\)
\(=5x^2\left(x^2-4\right)\)
\(=5x^2\left(x-2\right)\left(x+2\right)\)
i) \(7x^2-7y^2-14x+14y\)
\(=7\left(x-y\right)\left(x+y\right)-14\left(x-y\right)\)
\(=7\left(x-y\right)\left(x+y-2\right)\)
k) \(x^2+8x+24+3x\)
\(=x^2+11x+24\)
\(=x^2+3x+8x+24\)
\(=x\left(x+3\right)+8\left(x+3\right)\)
\(=\left(x+3\right)\left(x+8\right)\)
m) \(x^4-y^4\)
\(=\left(x^2-y^2\right)\left(x^2+y^2\right)\)
\(=\left(x-y\right)\left(x+y\right)\left(x^2+y^2\right)\)
n) \(x^6-y^6\)
\(=\left(x^3-y^3\right)\left(x^3+y^3\right)\)
\(=\left(x-y\right)\left(x^2+xy+y^2\right)\left(x+y\right)\left(x^2-xy+y^2\right)\)