for x ,
8x + 10x = 180°
[sum of linear pair is equal to 180°]
or, 18x = 180°
or, x = 180/18
therefore, x = 10°……
for z,
10z =8x
[ being corresponding angles are equal ]
or, 10z = 8 × 10°
( replacing x by 10°)
or, 10z = 80°
or, z = 80/10
thus z = 8°…………