# How do you solve #2sqrt(x+4) -1=x# and find any extraneous solutions?

##### 1 Answer

#### Answer:

In support of the answer by Mark E

#### Explanation:

Read his solution up to the point

Now Simplify:

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With quadratics if you can not spot the factorisation then it is wise to solve using the formula or completing the square.

Notice that the numbers

The 15 is negative in the given equation so we must have either

or

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The

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Thus we have:

Thus

Returning to Mark E's solution shows that -3 is not a valid solution

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