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Can someone help solve this problem

Can someone help solve this problem-example-1

1 Answer

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Answer:

  • x = 7 is a solution
  • x = -2 is an extraneous solution

Explanation:

The recommended method of solving this sort of equation is to ...

a) recognize that the denominators (x+2) and (x+3) are factors of the denominator (x^2 +5x +6).

b) multiply the whole equation by (x^2 +5x +6)

Doing this will give the equation ...

3 + (x -1)(x +3) = 7(x +2)

In standard form, this is ...

x^2 -5x -14 = 0

(x +2)(x -7) = 0 . . . . factored form

This has solutions x = -2 and x = 7.

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The original equation is undefined for x = -2 (and x = -3), so the solution x = -2 is extraneous.

The only solution is x = 7.

_____

Comment on avoiding extraneous solutions

If you don't try to eliminate fractions, but work with the equation as a rational equation, you get ...

(x +2)(x -7) / ((x +2)(x +3)) = 0

This reduces to

(x -7)/(x +3) = 0

which has one solution at x=7. The factor that results in the extraneous solution cancels itself from numerator and denominator.

Can someone help solve this problem-example-1
User Trebuchet
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