## anonymous one year ago Sophia is dilating a figure. One of her pre-image points with coordinates (-3, 5) has an image with coordinates (-9, 15). If one of the other image points has coordinates (3, 1), what are the coordinates of its pre-image point? (9, 3) (1,) (1, 3) (-3, -1) Which of these ordered pairs could not be a dilation of (8, -4)? (2, -1) (2, -2) (16, -8) (4, -2)

1. freckles

hey so -3*what=-9 5*what=15

2. anonymous

3

3. freckles

right

4. freckles

$3 \cdot (-3,5)=(3 \cdot (-3),3(5))=(-9,15)$

5. freckles

so what is 3 times (3,1)

6. freckles

$3 \cdot (3,1) =(3 \cdot 3,3 \cdot 1)=?$

7. anonymous

9,3

8. freckles

right

9. freckles

well (9,3)

10. freckles

$a \cdot (8,-4)=(8a,-4a)$

11. freckles

(2, -1) (2, -2) (16, -8) (4, -2) for which of these choices do you get a different a value that is : for example: let's look at the first point (2,-1) (8a,-4a)=(2,-1) 8a=2 gives a=1/4 -4a=-1 gives a=1/4 since both of these a's are the same than (2,-1) is a dilation of (8,-4)

12. freckles

try the others you want both a's to be the same

13. anonymous

okay

14. anonymous

..

15. freckles

what do the dots mean? does that mean you don't understand the example?

16. anonymous

no im thinking