Answer
$(x-3)(7x-1)$
Work Step by Step
For trinomials $ax^{2}+bx+c$ we search for factors of $ac$ whose sum is $b.$ If we find a pair, rewrite $bx$ and factor in pairs:
Here we find $-21$ and $ -1, $ factors of $ac=+21$, whose sum is $-22.$
$7x^{2}-22x+3=7x^{2}-21x-x+3$
$=7x(x-3)-(x-3)$
= $(x-3)(7x-1)$
