Answer: Choice D
Reflect over the y axis; dilate by a scale factor of 2.
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Explanation:
Let's focus on the bottom-most points of each rhombus. For rhombus A on the left, that point in question is (-3,1). For rhombus B, that corresponding lowest point is (6,2).
If we were to reflect rhombus A over the y axis, then (-3,1) would move to (3,1). Simply swap the sign of the x coordinate while keeping the y coordinate the same. Now compare (3,1) to (6,2). Notice that we can multiply each coordinate of (3,1) by the scale factor 2 so that we jump to (6,2)
[tex](3,1) \stackrel{\text{mult by 2}}{\longrightarrow} (6,2)[/tex]
This "multiply by 2" operation is done to each point of the reflected blue rhombus so that we end up with the green rhombus after all is said and done. Also, this trick of multiplying the coordinates by the scale factor only works if the center of dilation is the origin.
In short, we do two things:
- reflect over the y axis
- multiply each coordinate, of each point, by the scale factor 2
which allows us to go from blue (rhombus A) to green (rhombus B)
