1 ) \(x^2-y^2+14x+49=\left(x+7\right)^2-y^2=\left(x+y+7\right)\left(x-y+7\right)\)
2 ) \(x^2-24x-25=x^2+x-25x-25=\left(x+1\right)\left(x-25\right)\)
3 ) \(x^2-3xy=x\left(x-3y\right)\)
4 ) \(xy+xz-zy-z^2=x\left(y+z\right)-z\left(y+z\right)=\left(x-z\right)\left(y+z\right)\)
5 ) \(4x^3+8x^2y+4xy^2-16=4\left(x^3+2x^2y+xy^2-4\right)\)
6 ) \(3x^2-18x+27=3\left(x^2-6x+9\right)=3\left(x-3\right)^2\)
7 ) \(xy-y^2-x+y=y\left(x-y\right)-\left(x-y\right)=\left(x-y\right)\left(y-1\right)\)
8 ) \(x^2-5x+6=x^2-2x-3x+6=\left(x-2\right)\left(x-3\right)\)