Answer:
There is a few ways to answer this:
The actual and simple way: 19
The way we use for fun, (meme way): 910
Every multiples of 10s has a zero... you do know that... right?
I can’t see anything on the thing bro
A^2 - b^2 = (a-b)(a+b)
To test it, expand the right hand side.
If 7 is the value F it makes the equation true!