d: \(=\left(a+b\right)^2-c\left(a+b\right)=\left(a+b\right)\left(a+b-c\right)\)
e: \(=x^2-2x+1-4y^2-4y-1\)
\(=\left(x-1\right)^2-\left(2y+1\right)^2\)
\(=\left(x-1-2y-1\right)\left(x-1+2y+1\right)\)
\(=\left(x+2y\right)\left(x-2y-2\right)\)
f: \(=x^2\left(y-x\right)-9\left(y-x\right)=\left(y-x\right)\left(x-3\right)\left(x+3\right)\)