Answer:
17. D
18. C
Step-by-step explanation:
For both of these questions, you only need a general understanding of what rotation, translation, and dilation do. That is sufficient to let you choose the correct answer.
<h3>17.</h3>
The coordinates of Y are both negative, so it is a point in quadrant III on the graph. Rotating a point in quadrant III 270° clockwise will rotate it through quadrants II and I to quadrant IV, where it will be to the right and below the origin. Translation 9 units right and 5 units down will put it farther to the right and farther below the origin, still in quadrant IV.
As you know, translation right 9 units adds 9 to the x-coordinate. Translation down 5 units subtracts 5 from the y-coordinate. That means the coordinates of Y' must have x > 9 and y < -5. There is only one answer choice like that:
D. Y'(11, -8)
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<h3>18.</h3>
Dilation about the origin multiplies each coordinate by the scale factor. It does not change the quadrant of a point on the graph. The original coordinates of R are (negative, positive), so it is in quadrant II. The dilated point will still be in quadrant II, but will be closer to the origin. Both coordinate values will change.
R' = (1/3)R = (1/3)(-2, 3) = (-2/3, 3/3)
R' = (-2/3, 1) . . . . . matches choice C
