\(a,=\left(x+2\right)^2\\ b,=\left(x+4\right)^2\\ c,=\left(x+1\right)^2\\ d,=\left(x+3\right)^2\\ e,=\left(4x-1\right)^2\\ f,=\left(3x+1\right)^2\\ g,=\left(6x+3\right)^2\\ h,=\left(x+3\right)\left(x^2-3x+9\right)\\ i,=\left(x+1\right)^2\\ j,=\left(3x+y\right)^2\\ k,=\left(5a-2b\right)^2\\ l,=\left(x^2-2.\dfrac{1}{2}x+\dfrac{1}{4}\right)\\ =\left(x-\dfrac{1}{2}\right)^2\)