Question

DE is a line segment with endpoints D(-5,1) and E(3, 3). What are the coordinates of D’ and E’, the image of DE under a dilation of magnitude 1.5 and a center of dilation at the point (-4,2)?

Answer 1

First step is to calculate distance between point D and center of dilation:
x= |-4-(-5)| =1 
y= |2-1| =1

Now we multiply this distance by the dilation factor
x_distance = 1 * 1.5 = 1.5
y_distance = 1 * 1.5 = 1.5

Now we do same for point E:
x= |-4-3| =7 
y= |2-3| =1

Now we multiply this distance by the dilation factor
x_distance = 7 * 1.5 = 10.5
y_distance = 1 * 1.5 = 1.5

Now we need to find coordinates for points D' and E'.
Point D':
x = -4 - 1.5 = -5.5
y = 2 + 1.5 = 3.5
Point E':
x= -4 + 10.5 = 6.5
y= 2 + 1.5 = 3.5

D'(-5.5, 3.5)
E'(6.5,3.5)