0=z(z+4)
Rewrite the equation as z(z+4)=0.
z(z+4)=0
If any individual factor on the left side of the equation is equal to 0, the entire expression will be equal to 0.
z=0
z+4=0
Set the first factor equal to 0.
z=0
Set the next factor equal to 0.
z+4=0
Subtract 4 from both sides of the equation.
z=-4
z=-4
The final solution is all the values that make z(z+4)=0 true.
z=0,-4
Solve for z 0=z(z+4)