Sunday, August 19, 2012

Verify if the equation has any solutions 2x/(x+5)-x/(x-5)=50/(25-x^2) .

First, we'll impose the constraints of existence of the
fractions. All denominators have to be different from zero, for the fractions to
exist.


x + 5 different from 0 => x different from
-5


x - 5 different from 0 => x different from
5


The solutions of the equation can have any real value,
except the values {-5 ; 5}.


We'll solve the
equation:


2x(x-5) - x(x+5) =
50


2x^2 - 10x - x^2 - 5x =
50


We'll combine like
terms:


x^2 - 15x - 50 =
0


We'll apply quadratic
formula:


x1 = [15+sqrt(225 -
200)]/2


x1 = (15 + 5)/2


x1 =
10


x2 = (15-5)/2


x2 =
5


Since x2 = 5 is an exceted value, we'll reject this
solution.


The equation will have only one
real solution: x = 10.

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