Answer:
(3x + 5)(4x - 7)
Explanation:
The most common factors of 35 are 5 and 7. The 12 is a nuisance.
We could try 6 and 2 or 3 and 4 or even 12 and 1. You just have to juggle a bit to get the difference to be - x.
I'm going to try 3 and 4 first with 5 and 7. The numbers you get for the middle term have to be quite close.
(3x 5)(4x 7) Oops. It's going to come out first try.
Now you need to get the middle term come to - 1
(3x - 5)(4x + 7)
Just to make it slightly harder, I'll do it the wrong way first.
-5*4x + 3x*7 = - 20x + 21x = x That is close. Only the signs are incorrect.
So try again.
(3x + 5)(4x - 7)
20x - 21x = - x