Answer: The coordinates of point C after the dilation are (-2, 5)
Step-by-step explanation:
I guess that you want to find where the point C ends after the dilation.
Ok, if we have a point (x, y) and we do a dilation with a scale A around the point (a,b), then the dilated point will be:
(a + A*(x - a), b + A*(y - b))
In this case we have:
(a,b) = (2,1) and A = 3.
And the coordinates of point C, before being dilated, are: (1, 2)
Then the new location of the point C will be:
C' = (1 + 3*(1 - 2), 2 + 3*(2 - 1)) = (1 -3, 2 + 3) = (-2, 5)