a: \(3x^2-6xy+8x-16y\)
\(=\left(3x^2-6xy\right)+\left(8x-16y\right)\)
\(=3x\left(x-2y\right)+8\left(x-2y\right)\)
\(=\left(x-2y\right)\left(3x+8\right)\)
h: \(9y^2-4x^2+4x-1\)
\(=9y^2-\left(4x^2-4x+1\right)\)
\(=\left(3y\right)^2-\left(2x-1\right)^2\)
\(=\left(3y-2x+1\right)\left(3y+2x-1\right)\)