Question

HELP PLEASE!
Which of the following is NOT true concerning the equation x^2-c=0 for c>0?
A. The left-hand side of this equation is called a difference of two squares.
B. A quadratic equation in this form can always be solved by factoring.
C. A quadratic equation in this form can always be solved using the square root property.
D. This equation is not considered to be a quadratic equation because it is not of the form zx^2+bx+c=0.
(I have a feeling about D, but I don't know, might be utterly wrong.)

Answer 1

It's not D because x^2 - c is the same as 1x^2 + 0x + (-c)

notice how it matches the form ax^2 + bx + c where a = 1, b = 0, c is really -c

Answer 2

so x^2 - c = 0 is actually a quadratic equation

Answer 3

Oh yeah thought so wrote that down , thanks for the correction so it either be B or C?

Answer 4

x^2 - c is only factorable if c is a perfect square

example: x^2 - 4 = (x-2)(x+2)

in any other case, it's not factorable

The good news is that x^2 - c = 0 can be always be solved using the square root property

Answer 5

Like so..

\[\Large x^2 - c = 0\]

\[\Large x^2 - c+c = 0+c\]

\[\Large x^2 = c\]

\[\Large \sqrt{x^2} = \pm\sqrt{c}\]

\[\Large x = \pm\sqrt{c}\]

Answer 6

all that shows the square root property in action