Answer:
The method of solving "by substitution" works by solving one of the equations (you choose which one) for one of the variables (you choose which one), and then plugging this back into the other equation, "substituting" for the chosen variable and solving for the other. Then you back-solve for the first variable.
Step-by-step explanation:
Hope this helps you
 
        
                    
             
        
        
        
Answer:
80°
Step-by-step explanation:
Just multiply 40° by 2 to get the arc
 
        
                    
             
        
        
        
Answer:
X = 6 1/2
Step-by-step explanation:
X is equal to 6 1/2 because, if you subtract 3 1/2 from 10 you will be left with 6 1/2.