Factoring?

Question

xsquared -28x-147=0
i can only come up with 3, 49, and 7,21 but that doesnt work can this even be factored?

but -7x-21 = a positive 147 not a negative

Answer 1

x^2 - 28x - 147 = 0

x = (-b ± sqrt(b^2 - 4ac))/(2a)

x = (-(-28) ± sqrt((-28)^2 - 4(1)(-147)))/(2(1))
x = (28 ± sqrt(784 + 588))/2
x = (28 ± sqrt(1372))/2
x = (28 ± sqrt(4 * 49 * 7))/2
x = (28 ± sqrt(196 * 7))/2
x = (28 ± 14sqrt(7))/2
x = 14 ± 7sqrt(7)

This problem cannot be factored

Answer 2

it's impossible...

if the equation is x^2-28x+147=0 then, the answer would be x=7, 21

Answer 3

Using the quadratic formula as shown by Sherman81 above, you get that the roots are x = 14 ± 7sqrt(7). That means that the original expression can be factored as (x - (14 + sqrt(7)))*(x - (14 - sqrt(7))). There's nothing wrong with those expressions, but they would generally be considered to be less simplified than the original trinomial.

Answer 4

x^2-28x+147=0

use the factoring equation:
[-b(+or-)sqrt(b^2-4ac)]/2a

[28+sqrt(784-588)]/2
and
[28-sqrt(784-588)]/2

[28+14]/2
and
[28-14]/2

x=21, 7