A scale factor of a dilation is greater than 1, then it is an expansion and if it is less than 1, then it is a contraction.
From the given values, scale factors 0.9, 3/8 -6 refer to a contraction and 5 and 8/5 refer to an expansion.
Example:
Consider any shape with area 40 square units.
Then,
40(0.9) = 36 < 40
40(3/8) = 15 < 40
40(-6) = -240 < 40
So, 0.9, 3/8 and -6 refer to contractions.
Now,
40(5) = 200 > 40 and
40(8/5) = 64 > 40
So, 5 and 8/5 refer to expansions.
