The two angles form a straight line which is equal to 180 degrees. This makes the angles supplemtary.
To find x, add the two angles together to equal 180:
7x + x+20 = 180
Combine like terms:
8x + 20 = 180
Subtract 20 from both sides:
8x = 160
Divide both sides by 8:
X = 20
 
        
                    
             
        
        
        
Answer:
2x/5 <14
Step-by-step explanation:
 
        
             
        
        
        
<span> 3x+2/2 = 7. First, multiply 2 to both sides and you get 3x+2=14. Then, just solve using backward PEMDAS. The answer is 4. </span>
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Hello from MrBillDoesMath!
Answer:
See below
Discussion:
Triangles BAD and BCD are congruent by the SAS postulate.
           * Side AD = DC because BD is the perpendicular bisector  of AC. 
           * Angle ADB and CDB are both right angles, and hence equal, because
             BD is the perpendicular bisector of AC)
Corresponding parts of congruent triangles are equal so angle BAD = angle BCD,  which was to be proven.
Regards,  
MrB