PSAT #2, Section 3, #16
OK, so you’re told that 
is a factor of 
. You need to find 
. To do so, you’ll need to set up a classic FOIL scenario. I’m going to use 
and 
for the unknowns in the second factor.
Now remember what happens when you FOIL. The 
and the 
will combine to make the 
, and the 
will combine with the second to make 
. Therefore, it must be true that 
and 
. We can use that information to solve for .
