What property is being used im step one? will mark brainliest!

Step-by-step explanation:

3a+6=2+7−5a

3a+6=2+7+−5a

3a+6=(−5a)+(2+7)

3a+6=−5a+9

3a+6=−5a+9

Step 2:  

3a+6+5a=−5a+9+5a

8a+6=9

Step 3:

8a+6−6=9−6

8a=3

Step 4:

8a/8 = 3/8

a=3/8

a = 3/8

true? is that what you're asking or do you mean something else?

is this part of a question or something