Question

factor
HOW DO YOU FACTOR TRINOMIALS?? any formulas?????
4x² - 5x - 21

Answer 1

omg so many peolpe here XD...

Answer 2

We have constants 4, -5 and -21

What you are looking for is what numbers (2) summed, get -5, and multiplifed, -21*4.

Answer 3

hm.. only mulitples of 21 are 7 and 3, but how would they add up to -5?

Answer 4

here is solution...

Answer 5

uhm, how did you exactly get the steps? like what did you do to get to the next step? I don't know how you got the next numbers...

Answer 6

-21*4 = -84 right?

Answer 7

So what numbers multiplied gives -84?
I found 6*-14, 7*-12 and some others.

Answer 8

Then 7+-12 = 7-12 = -5, so our two numbers is 7 and -12
Now you can rewrite your trinomials into this form:
\(4x^2 +7x -12x -21\)

Answer 9

and by factoring out some stuffs out
\(4x^2-12x+7x-21\)
\(4x(x-3)+7(x-3)\)
\((4x+7)(x-3)\)

Answer 10

check my attachment you get answer...

Answer 11

ohhh I see now. kk thanks guys

Answer 12

welcome