How do you factor 2x^2+3x-20?

1 Answer
Nov 9, 2015

(x+4)(2x-5)

Explanation:

The left and right side of the polynomial:
5xx (4)=20
2xx(-1)=2

How can multiply those together and add to 3?
5xx-1 = -5
and
2xx4 = 8
If we add -5+8, we get 3!!!

Because we need 1x*(-5)=-5x
and
2x*4=8x
We put each term across from each other.
So its like cross multiplying

(1x+4)
(2x-5)

Try if you get the middle term of 3x
(1x*-5)+(2x*4)=3x

Now the answer can be written as (x+4)(2x-5)