Answer:
B
Step-by-step explanation:
The "..." at the end of B tell us that it's a repeating decimal so B is irrational. Of course, you can't use this reasoning for every repeating decimal but in this case it works.
Given:
The point is B(2,5) and its image is B'(1,2.5).
To find:
The scale factor.
Solution:
If a figure is dilated by the scale factor k and (0,0) is the center of then the scale factor is defined as
x-coordinate of point B' is 1 and the x-coordinate of point B is 2. So, the scale factor is
Therefore, the scale factor is 
and the correct option is D.
First, you should substitute the variables for their value in the expression.
= [ 3 (-0.5) (4)² - (-3) ] / (-0.5)
= [ 3 (-0.5) (4)² + 3 ] / (-0.5)
= [ 3 (-0.5) (16) + 3 ] / (-0.5)
= [ (-1.5) (16) + 3 ] / (-0.5)
= [ (-1.5) (16) + 3 ] / (-0.5)
= (-24+3) / (-0.5)
= -21 / -0.5
= 42
