Step-by-step explanation & answer:
When a dilation in the coordinate plane has the origin as the center of dilation, we can find points on the dilated image by multiplying the x and y coordinates of the original figure by the scale factor.
For example, if the scale factor is "k", the algebraic representation of the dilation is
(x, y) → (kx, ky)
For enlargements, k > 1 and for reductions, k < 1.
Hope this is what you needed:)
 
        
             
        
        
        
Answer: D 
Step-by-step explanation:
If segment D moves downward it means its function has a negative slope so the line will be  decreasing.  
 
        
             
        
        
        
It would be the 2nd one 35 divide by 7=5
        
                    
             
        
        
        
Answer:
a = 50t
Step-by-step explanation:
The graph goes through (0,0) so the y intercept is 0
a=5t
a=50t
a=50 + t    not it
a=10t 
The slope is  y/x since the y intercept is 0
m = 50/1 = 50
The equation for the line is 
y = 50x+0
y = 50x
Using the variables given
a = 50t