## Algebra 2 (1st Edition)

$f=-1$
The two possibilities are $f+3=2f+4$ or $-f-3=2f+4$ The first equation, after subtracting f-4 from both sides, gives f=-1 which when plugging back in gives |2|=|2| The other equation gives $f=-7/3$ which when plugging back in gives, |some number | = some negative number, Which is extraneous since an absolute value cannot yield a negative number.