Answer:
(3x + 1)(x + 7)
Explanation:
3x² + 22x + 7 =
3x² must factor into 3x and x.
= (3x + )(x + )
7 factors into 7 and 1. We can place 7 and 1, or 1 and 7.
= (3x + 7)(x + 1)
or
= (3x + 1)(x + 7)
Now we multiply both possibilities out to see which one produces the middle term 22x that we need.
= (3x + 7)(x + 1) = 3x² + 10x + 7 No what we need
or
= (3x + 1)(x + 7) = 3x² + 2x + 7 Exactly what we need
Answer: (3x + 1)(x + 7)