factoring quadratic equations?

Question

- x sqrt - 11x - 28 = 0

Answer 1

Did you mean to say square root or did you mean squared??

If you mean x squared, then

Multiply thru by -1 and factor

(x + 7)(x + 4) = 0

x = -7, x = -4
.
.

Answer 2

I'll assume that the first term is actually x^2.

Now, I personally find it easier to deal with positive x^2 terms, so multiply both sides of the equation by -1.

Now, you have:

x^2+11x+28 = 0

Now, if the roots are rational, then you need to find the factors of 28 which when added together give you +11.

It turns out that 4 and 7 do just that. So, the factors of this quadratic are:

(x+4)(x+7) = 0

Now, to solve, set each factor =0, and you get:

x+4 = 0 or x = -4
x+7 = 0 or x= -7

Answer 3

Presuming you meant squared and not square root:

-x^2 - 11x - 28 = 0
-1 * (x + 7)(x + 4) = 0
(x+7)(x+4) = 0
x = -7, -4