\(1,=\left(x-3y\right)^2\\ 2,=\left(x-5y\right)\left(x+5y\right)\\ 3,=\left(3x-y\right)\left(3x+y\right)-\left(3x-y\right)=\left(3x-y\right)\left(3x+y-1\right)\\ 4,=\left(x-y\right)\left(x+y\right)+\left(x-y\right)=\left(x-y\right)\left(x+y+1\right)\\ 5,=\left(x-5y\right)\left(x^2+5xy+25y^2\right)\\ 6,=\left(x-2\right)^2-y^2=\left(x-y-2\right)\left(x+y-2\right)\\ 7,=x\left(x-3\right)+y\left(x-3\right)=\left(x+y\right)\left(x-3\right)\\ 8,=m\left(x+3\right)+2y\left(x+3\right)=\left(2y+m\right)\left(x+3\right)\\ 9,=x\left(x-1\right)\left(x+1\right)\\ 10,=\left(x^2+2xz+z^2\right)-\left(4y^2-4y+1\right)\\ =\left(x+z\right)^2-\left(2y-1\right)^2\\ =\left(x+z-2y+1\right)\left(x+z+2y-1\right)\)
