answersLogoWhite

0

Suppose you have the expression x2 + 7x + 12. You look for two numbers that add to 7 and multiply to make 12. They are 3 and 4. You put these numbers into the factors as follows: (x+3)(x+4).

<>

Here is a harder example. x2 - 5x - 36. The numbers have to multiply to make -36, so one must be negative and the other positive. Since they add to -5, the big number must be negative. If you're stuck, make a list of the pairs of factors of 36: 1x36, 2x18, 3x12, 4x9, 6x6. The numbers we are looking for are 4 and -9, and the factors are (x+4)(x-9).

<>

These two examples are 'easy' trinomials, since they have no number in front of the x2. 'Hard' trinomials do have a number there. For example, 3x2 - 19x -14. There are several ways of doing this, but it is basically organized trial and error. The factors are (3x+2)(x-7).

User Avatar

Wiki User

12y ago

Still curious? Ask our experts.

Chat with our AI personalities

RossRoss
Every question is just a happy little opportunity.
Chat with Ross
EzraEzra
Faith is not about having all the answers, but learning to ask the right questions.
Chat with Ezra
LaoLao
The path is yours to walk; I am only here to hold up a mirror.
Chat with Lao

Add your answer:

Earn +20 pts
Q: How do you find the factors of quadratic expressions?
Write your answer...
Submit
Still have questions?
magnify glass
imp