How do you solve \frac { 6} { x + 3} = \frac { 9x } { x ^ { 2} - 9}?

1 Answer
Jul 22, 2017

Use the formula of multiplying polynomials:
(x+y)(x-y)=x^2-y^2
and use Least Common Denominator (LCD) to isolate and solve for x.

Explanation:

6/(x+3)=(9x)/(x^2-9)

Simplify by making the common denominator between the two fractions.

(6(x-3))/(x^2-9)=(9x)/(x^2-9)

You can now get rid of the denominators.

6(x-3)=9x

Solve for x.

-3x=18
x=-6