1)
[tex]\bf 3x^{2} -48 = 0[/tex]
[tex]\bf 3\cdot(x^{2} -16) = 0[/tex]
[tex]\bf 3\cdot(x^{2} -4^{2}) = 0[/tex]
[tex]\bf 3\cdot(x+4)\cdot(x-4) = 0[/tex]
[tex]\bf (x+4)\cdot(x-4) = 0[/tex]
[tex]\bf x+4 = 0 \Rightarrow \boxed{\bf x_{1} = -4}[/tex] ∈ IR
[tex]\bf x-4 = 0 \Rightarrow \boxed{\bf x_{2} = 4}[/tex] ∈ IR
2)
[tex]\bf x^{2} = 0\Rightarrow x=0[/tex] ∈ IR
