Explanation: The general rule to get the new dilation coordinate is as follows: new coordinate = k * old coordinate where k is the scale factor
For point A: Xcoordinate of A' = k * Xcoordinate of A -7 = k * -21 k = -7 / -21 k = 1/3 Ycoordinate of A' = k * Ycoordinate of A 6 = k * 18 k = 6/18 k = 1/3
For point C: Xcoordinate of C' = k * Xcoordinate of C -4 = k * -12 k = -4/-12 k = 1/3 Ycoordinate of C' = k * Ycoordinate of C 3 = k * 9 k = 3/9 k = 1/3
From all of the above, we can conclude that the scale factor is definitely 1/3
