Answer:
1. 13
2. 18
3. 7
4. 12
Explanation:
Well, the total of angles in the triangle should equal to 180
1. (8x - 35) + (6x - 5) + (3x - 1) = 180
⇔ x =

⇔ x = 13
2. (5x - 11) + (2x + 20) + [180 - (11x - 63)] = 180
⇔ x =

⇔ x = 18
3. It's Equilateral Triangle.
(9x - 3) =

⇔ x = 7
4. It's Isosceles triangle.
(8x - 23) =

⇔x =

⇔x = 12