Answer:

Explanation:
9. For the lines 'm' and 'n' to be parallel the sum of interior angles should be 180 degrees that is:


10. For the lines 'm' and 'n' to be parallel the alternate exterior angles should be equal that is:



11. For the lines 'm' and 'n' to be parallel alternate angles should be equal that is:

Solving for 'x' we get:



12. For the lines 'm' and 'n' to be parallel corresponding angles should be equal that is:



