Answer:14
Step-by-step explanation:
x + 7 = 21
group like terms
x = 21 - 7
When positive cross = sign it turns negative
x = 14
30 minutes is half of an hour so it would be 50%.
Answer:35
Step-by-step explanation: uhhhhh google
Two intersecting lines will form 2 pairs of congruent vertical angles. Congruent angles have the same angle measure and vertical angles are opposite angles formed by two intersecting lines. Hope this helps.