So starting with the x variable:
Using the vertical angles theorem, we can make the equation [tex]15x-44=91[/tex] and solve from there.
Add 44 on each side to get [tex]15x=135[/tex]
Divide 15 on each side to get [tex]x=9[/tex]
Next with the Z variable:
Using the linear pair theorem, we can make the equation [tex]91+z=180[/tex] and solve.
Just subtract 91 on each side to get [tex]z=89[/tex] .
