Question

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)

Answer 1

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

Answer 2

3

Answer 3

right

Answer 4

\[3 \cdot (-3,5)=(3 \cdot (-3),3(5))=(-9,15)\]

Answer 5

so what is 3 times (3,1)

Answer 6

\[3 \cdot (3,1) =(3 \cdot 3,3 \cdot 1)=?\]

Answer 7

9,3

Answer 8

right

Answer 9

well (9,3)

Answer 10

\[a \cdot (8,-4)=(8a,-4a) \]

Answer 11

(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)

Answer 12

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

Answer 13

okay

Answer 14

..

Answer 15

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

Answer 16

no im thinking