It can, it just depends upon the slope
Do you know what the slope is?
Let's look at the corresponding ratios:

And we see that the three aren't equal.
Hence, $\Delta ABC$ and $\Delta EDC$ are not similar.
In order to subtract fractions, you need the denominators (bottom number) to be the same.

.
Answer:
1. 60. 2. -6. 3. -4/5
Step-by-step explanation:
Okay so I haven't done slope in 3 years but I used to be a god at it so please tell me if you get this right and I'm so so sorry if you get them wrong