\(4,\\ f,=\left(x-1\right)\left(x+1\right)\\ g,=\left(y-2\right)\left(y+2\right)\\ h,=4\left(1-z\right)\left(1+z\right)\\ i,=\left(c-5\right)\left(c+5\right)\\ j,=\left(3y-x\right)\left(3y+x\right)\\ k,=\left(y-x\right)\left(y+x\right)\\ l,=\left(2a-3b\right)\left(2a+3b\right)\\ m,=\left(x-z-t\right)\left(x-z+t\right)\\ 5,\\ a,=\left(x+1-1\right)^2=x^2\\ b,=\left(y-1+1\right)^2=y^2\\ c,=\left(z+2-2\right)^2=z^2\\ 6,\\ a,\Rightarrow x^2+2x+1-x^2+x=0\\ \Rightarrow3x=-1\Rightarrow x=-\dfrac{1}{3}\\ b,\Rightarrow x^2-6x+9-x^2+x+2=0\\ \Rightarrow-5x=-7\Rightarrow x=\dfrac{7}{5}\\ c,\Rightarrow x^3+3x^2+3x+1+1-3x+3x^2-x^3=8\\ \Rightarrow6x^2=6\Rightarrow x^2=1\Rightarrow\left[{}\begin{matrix}x=1\\x=-1\end{matrix}\right.\)
\(d,\Rightarrow x^3-3x^2+3x-1-x^3-27+3x^2-12=2\\ \Rightarrow3x=42\Rightarrow x=14\)
