In the given figure BD || CE, find x, y, z.

angle DBA =70°(vertically opposite angles)
angle BDA=180°-120°(linear pair)
=60°
angle DBA+BDA+X=180° (angle sum property of a triangle)
70°+60°+X=180°
130°+X=180°
X=180°-130°
X=50°
Now,
angle BDE=180°-120°(Linear pair)
=60°
then,
angle Y =angle BDE(corresponding angles)
60°=60°