Answer:0.0009765625
Step-by-step explanation:
Start by multiplying the 9 out:
9(-6 + 8y) = -54 + 72y
Then, add the 7:
-54 + 72y + 7
Then simplify the whole thing:
-47 + 72y
Attached solution with detailed work.
You can remove the % sign if you divide the number by 100:

This is because % is defined as 1/100, and the name (per-cent) actually meant this originally!
we can also simplify it: let's divide it by 4: