<u>Answer:</u>
<u>Step-by-step explanation:</u>
- 10 + 4.5m = 21.25
- => 4.5m = 21.25 - 10
- => 4.5m = 11.25
- => m = 11.25/4.5
- => m = 2.5
<u>Conclusion:</u>
Therefore, m = 2.5
Hoped this helped.

Answer:
Step-by-step explanation:
Reasons
2. If two lines are parallel, their corresponding angles are congruent.
3. Congruent angles are equal... Why do they even have this step?
4. A straight line forms a linear pair.
5. Angles in a linear pair are supplementary.
6. ∠1 is supplementary to ∠3. Reason: If an angle is congruent to an angle that is supplementary to a third angle, the first and third angles are congruent OR Transitive Property.