Hey there! 
1. 5(s-2) This is because s-2 is the length of each side, and there are 5 sides in a pentagon all of that length, so multiplying it by 5 like this shows its perimeter. 
2. 5s-10 This can be found by distributing the first equation, multiplying both s and -2 by 5. 
3. (s-2) + (s-2) + (s-2) + (s-2) + (s-2) Each grouping in the parenthesis represents each of the 5 sides, so adding them all together will get you the perimeter. 
4. 5(s) + 5(-2) This one is most like the first one, except it's a little more spread out. Multiply the term s by the 5 sides in one grouping, and the integer -2 by 5 in the other. 
Hope this helps!
 
        
             
        
        
        
So firstly, we have to find f(x) when x = 8 and x = 0. Plug the two numbers into the x variable of the function to solve for their f(x):

Now that we have their y's, we can use the slope, aka average rate of change, formula, which is  . Using what we have, we can solve it as such:
 . Using what we have, we can solve it as such:

In short, the average rate of change from x = 0 to x = 8 is 5/21.
 
        
             
        
        
        
I suck at explaining but I know it’s 4
        
             
        
        
        
2,640,000. Because the 4 is in the ten thousands place and should be rounded up
        
                    
             
        
        
        
Answer:
Step-by-step explanation:
D²=290²+2030²
=290²+(290×7)²
=290²+290²×7²
=290²(1+7²)
=290²(1+49)
=290²×50
=290²×25×2
=290²×5²×2
D=290×5×√2
D=1450√2