Re: I don't know why I'm getting the correct answer


Pious Audio wrote:
I really appreciate the patience on this board; you all don't know how
much help you are.

Here's the deal, the direction of a problem I'm working on says:
"solve the following equations by the method of forming a new equation
whose roots are "larger" than those of the original equation by
one-half the coefficient of x."

x^2 + 12x + 9 = 0

so I do as ordered:

y = x + 12/2 = x + 6

x = y - 6

(y - 6)^2 + 12 (y - 6) + 9 = 0

+36 - 72 + 9 = - 27; I think.

y^2 = 27

y = (27)^(1/2) y = -(27)^(1/2)

x = (27)^(1/2) - 6 x = -(27)^(1/2) - 6

That's all well-and-good, and the book says that I've produced the
correct answer. However, if I plug the durrived value of x into the
original equation, it doesn't equal zero, it equals 9. What's up?

.

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