4x+8=0⇒4x=-8⇒x=-2
x+3=0⇒x=-3
x -2 -3
4x+8 --------------------0++++++++++++++++++++++++++
x+3 -----------------------------------------------0+++++++++++
[tex] \frac{4x+8}{x+3} [/tex] ++++++++++++0-------------------------0+++++++++++
x apartine (-infinit,-2]reunit [-3,infinit)