Answer:
y = 35°
Step-by-step explanation:
if the lines are parallel, the alternate interior angles theorem applies ("if a transversal intersects two parallel lines then alternate interior angles are congruent"). so since we know that the lines are parallel, the alternate interiors are congruent so 70=2y. from there, divide both sides by 2 to isolate y (division property of equality) and y=35.
