Answer:
76 degrees
Step-by-step explanation:
We know that supplementary angles equal 180 degrees. So, set up the equations:
[tex]180=(x+15)+(x-13)\\[/tex]
[tex]180=(2x+2)\\[/tex]
[tex]178=2x[/tex]
[tex]x=89\\[/tex]
Then, you just plug 89 back into ZB, and simplify:
[tex](89-13)\\[/tex]
[tex]=76[/tex]
So, the measurement of angle ZB is 76 degrees.