Answer:
(x, z) = (7, 69)
Explanation:
Easy first: 69° and z° are vertical angles, so congruent:
z = 69
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The angle marked with an expression in x is supplementary to either of the other two:
(6x +69)° +69° = 180°
6x = 42 . . . . . . . . . . . . divide by °, subtract 138
x = 7 . . . . . . . . . . . . . . divide by 6