Answer:
7(x+3)
Step-by-step explanation:
7x+21
7x = 7*x
21 = 7*3
We can factor out a 7 from both terms.  What remains is what is inside the parentheses
7(x+3)
 
        
                    
             
        
        
        
Answer:
D
Step-by-step explanation:
Common ratio of half means that to get each successive terms, you have to multiply the preceding term by half.
Since first term is 10
2nd term is 
3rd term is 
4th term is 
5th term is 
Answer choice D is right.
 
        
                    
             
        
        
        
Answer:
80 in^2
Step-by-step explanation:
8*4=32
32/2=16
16= One triangle
16*4 triangles=64
4*4=16
64+16=80
 
        
             
        
        
        
Let the speed off the walk way be x and speed of the walkway be y
x+y=6....i
x-y=2....ii
adding the above equation we get:
2x=8
thus
x=4 ft/s
and
y=6-4=2 ft/s
thus the speed off the walk way is 4 ft/s
the speed of the moving walkway is 2 ft/s