These are already factored as far as they can be. However, if you were looking to multiply them to get their polynomial, it would be 48f^2 -110f + 63.\
You can get this by using the term FOIL
First - Multiply the first numbers in each parenthesis.
6f * 8f = 48f^2
Outer - Multiply the outer numbers in each parenthesis.
6f * -9 = -54f
Inner - Multiply the inner numbers in each parenthesis.
-7*8f = -56f
Last - Multiply the last numbers in each parenthesis.
-7*-9 = 63
Now combine them all and simplify.
48f^2 - 54f - 56f + 63
48f^2 - 110f + 63