We need to isolate on the equation
[tex]8+(z\times1)=0[/tex]since any number multiplied by one is the same, then z times 1 is z, so we can write
[tex]8+z=0[/tex]Now, we can add -8 to both side and get
[tex]8-8+z=-8[/tex]since 8 - 8 is zero, we have
[tex]z=-8[/tex]then, z is equal to -8.