\(4,\\ a,=\left(x-3\right)^2\\ b,=\left(3x+1\right)^2\\ c,=\left(5x-3y\right)\left(5x+3y\right)\\ d,=\left(x-2\right)\left(x^2+2x+4\right)\\ e,=\left(2x+1\right)\left(4x^2-2x+1\right)\\ f,=\left(x-3\right)^3\\ g,=\left(a+b-1\right)^2\\ h,=\left(a+2\right)^3\\ i,=\left(x^2+4-4x\right)\left(x^2+4+4x\right)=\left(x-2\right)^2\left(x+2\right)^2\\ u,=\left(x+y+z-2z\right)\left(x+y+z+2z\right)\\ =\left(x+y-z\right)\left(x+y+3z\right)\)
\(5,\\ a,=\left(x+y\right)^2=\left(2004-2003\right)^2=1^2=1\\ b,=\left(x+4\right)^3=\left(-4+4\right)^3=0^3=0\)