How do you factor $5n^2 + 19n + 12$ ?

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Answer 1 · 2015-05-22T13:39:10

$5n^2+19n+12$

We are looking for factors of $5 = axxb$
and of $12 = cxxd$
such that
$axxc+bxxd = 19$

Fortunately that are relatively few factor possibilities
$5 = 5xx1$
and
$12 = (3xx4) " or " (2xx6) " or " (1xx12)$

and a suitable set is easily found, giving
$(n+3)(5n+4)$

How do you factor 5n^2 + 19n + 125n^2 + 19n + 12?