Answer:
5a
Step-by-step explanation:
 
        
             
        
        
        
Add all the number, and then divide it by number of numbers.
for example, 1, 2, 3, 7, 10
(1+2+3+7+10)/5
23/5 = 4.6 The average is 4.6
 
        
             
        
        
        
Answer:
28 , 28, -14
Step-by-step explanation:
x2+6x+8=0
4(2)+6(2)+8=0
8+12+8=0
28=0
x2+6x+8=0
-4(2)+6(2)+8=0
8+12+8=0
28=0
x2+6x+8=0
-8(2)+6(-1)+8=0
-16-6+8
-14=0
 
        
             
        
        
        
Answer:
1
Step-by-step explanation:
(-2)^2 +5(-2)+7=
= 4-10+7=
=1