we can divide the composite shape into on quadrilateral and triangle as shown in the diagram. since the line that joins the two shape is parallel to the base AB, the angle DEC is 85°.The angle CEA is 180°- angle DEC = 180-85=95. Angle BCE is sum of angle CEA, ABC and EAB subtracted from360°= 360°-(95+95+85)=85°. Angle DCE is 120°- ECB=35°. So, angle CDE = 180°-(35°+85°)= 60°. For reference see the diagram. 
 
        
             
        
        
        
It's been such a long time, but I think (1) should be the addition property since your adding 5 to both sides.
And (2) should be the multiplication property due to multiplying both sides by 2.
        
             
        
        
        
You can use a square plus b square equal C square to fijd each length . or you can memorize the special triangles or you can also do proportional problem. it all works
        
             
        
        
        
Answer:
12
Step-by-step explanation:
Since the two angles are vertical angles, they are congruent and therefore 6x+7=8x-17
2x=24
x=12
Hope this helps! PM me with more questions.
 
        
                    
             
        
        
        
Domain: x values
Range: y values
The relation would need to have (2, y) and (4, y). And also (x, 2) and (x, 8)
See which ones match
Solution: B