What is the factors for x^2-x-20x2x20?

2 Answers
Mar 24, 2018

(x-5)(x+4)(x5)(x+4)

Explanation:

What factors of -2020 add up to the value of b which is -11?:
4, -54,5

-4, 54,5

10, -210,2

-10, 210,2

20, -120,1

-20, 120,1

It would be 4, -54,5, therefore:
(x-5)(x+4)(x5)(x+4), since a is equal to 1

Mar 24, 2018

x^2-x-20 = (x+4)(x-5)x2x20=(x+4)(x5)

Explanation:

x^2-x-20x2x20

In order to factor, we have to find factors of -2020 that when summed together give us -11 (since -11 is the coefficient of the middle term).

Factors of -2020:
(-1, 20),(1,-20),(2,-10),(-2, 10),(-4,5),color(blue)(((4,-5)))

We see that (4,-5) has two factors for -20 that when summed together equals -1.

So we can write our factor form:

x^2-x-20 = (x+color(blue)(4))(xcolor(blue)(-5))