Geometry

Question Analysis
This question involves solving for the variable x given two parallel lines cut by a transversal, with angle measures expressed algebraically. The focus is on identifying the relationship between given angles and using it to set up an equation for x.

Key Concept Explanation
When two parallel lines are cut by a transversal, corresponding angles are in the same relative position at each intersection. The key property is that corresponding angles are congruent.

Step-by-Step Solution
∵ m∥n (Given)
∴ m∠3 = m∠7 (Corresponding Angles Postulate)
∵ m∠3 = (3x + 10)° and m∠7 = (5x - 20)° (Gi...