20.9 cause you just subtract everything from the original number
        
             
        
        
        
Acute and Right Angle, this is all I know
Hope I'm right though 
 
        
                    
             
        
        
        
Answer:
15
Step-by-step explanation:
 
        
             
        
        
        
A way that I use to determine if something is a function or not is to ask whether or now it passes the “vertical line test”. In other words, does an x have two y’s? if we graphed these points, and proceeded to draw a vertical line through it, if it touches the function twice, then it is not a function. So I believe your answers would be A and C (In A, when x is 2, there are two y’s. Same goes with C, when x is 1, 4, 9 etc). 
I hope this answer helps! :)
        
             
        
        
        
Answer:
The step 4 and 5 describe the errors Stephen made.
Step-by-step explanation:
Given : Stephen evaluated 
.  His work is shown below.
To find : Which two statements describe the errors Stephen made?
Solution : 
Step 1 - 
Step 2 - 
Step 3 - 
Step 4 - 
Error is the step as 4 sign is negative.
So correct step is 
Step 5 - 
Error is the step as there is 4 in place of 3.
So correct step is 
The step 4 and 5 describe the errors Stephen made.