a: \(=xy\left(x^2+2xy+y^2\right)=xy\left(x+y\right)^2\)
b: \(=2xy\left(x^2-9\right)=2xy\left(x-3\right)\left(x+3\right)\)
c: \(=\left(x-y\right)^2-25\)
\(=\left(x-y-5\right)\left(x-y+5\right)\)
d: \(=3x^2\left(1-3x\right)\)
e: \(=25-\left(a-b\right)^2\)
\(=\left(5-a+b\right)\left(5+a-b\right)\)