Answer:
A
Step-by-step explanation:
it goes down by 9 and left by 3
Thats either 7/5 or 1 2/5 but since theres a whole number i think its 1 2/5
19. -x-2 = 2/3x + 3
5/3 x + 3 = -2
5/3x = -5
x = -3
20. none are correct, you can double check me by plugging in the x and y values in the coordanates into the first problem none of them worked out in the first equasion so no need to test the second
21. -3 is the answer, capable of being done by using desmos
Answer:

Step-by-step explanation:
Given

Rotation = +270 degrees
Required
Determine the new coordinates of Q (i.e. Q')
When a point (x,y) is rotated +270° about the origin, the new coordinates is: (y,−x)
So:

Where:
and 
Q' will be:

Answer:
Answer choice A
Step-by-step explanation:
This is the midpoint of both coordinates.