Answer:
9. (3x + 11) + 25 + 90 = 180
11. 3x + 45 = 180
Explanation:
I can't see number 8 and 10, so I can only solve 9 and 11.
9. Ok, so the sum of the interior angles of a triangle equals 180 degrees (translation: add the inside angles of the triangle and they equal 180)
The little square in the corner of the triangle means it's a right angle. Right angles are 90 degrees. So now you have 3 angle measures. Set their sums equal to 180.
3x + 11 + 25 + 90 = 180 (I'm not doing all of the work for you. It's pretty easy to solve for x from here)
11. Supplementary angles add up to 180 degrees (translation: the two angles that share a vertex, ray, and form a straight line add up to 180)
3x + 45 = 180 (again, it's very simple to solve for x from here, so I will let you do that)
I really hope this helps you. If you need more help solving, please ask =)