Answer:
77°
Step-by-step explanation:

 
        
                    
             
        
        
        
The subtraction property of inequality can be used to proof that x = 7 from  x + 8 = 15
<h3>What is an 
equation?</h3>
An equation is an expression that shows the relationship between two or more variables and numbers.
Given that x + 8 = 15
Hence:
x + 8 - 8 = 15 - 8 (subtraction property of inequality)
x = 7
The subtraction property of inequality can be used to proof that x = 7 from  x + 8 = 15
Find out more on equation at: brainly.com/question/2972832
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Answer:
the answer is C 
Step-by-step explanation:
because the negative needs to be on the inside not on the outside
 
        
                    
             
        
        
        
Answer:
2
Step-by-step explanation:
substitute n=1 and n=3 in the given equation
1 st term is (1)^2-1-2 = 1 -1 -2 = -2
3rd term is (3)^2-3-2 = 9-3-2=4
sum of 1st and 3rd term is -2 + 4 = 2