Answer:
x=9, z=120
Step-by-step explanation:
A line has angle of 180 degrees so:
[tex](12x-48)+(9x+39)=180\\21x-9=180\\21x=189\\x=9[/tex]
Diagonal angles are equal so:
[tex]9x+39=z[/tex]
Substitute the first equation into the second:
[tex]9(9)+39=z\\z=81+39\\z=120[/tex]
Hope that helps!!!
