Answer:
x = 4°
Z = 71°
Explanation:
Linear pair:
If the non-common arms of two adjacent angles form a straight line, then they are called linear pair and they add up to 180°.
12x + 23 + 15x + 49 = 180°
12x + 15x + 23 + 49 = 180°
Combine like terms,
27x + 72 = 180°
27x = 180 - 72
27x = 108
x = 108 ÷ 27

12x + 23 = 12*4 + 23
= 48 + 23
= 71°
Z = 71° {Vertically opposite angles are equal}