Given the equation [tex]\sqrt{2x + 1} = 3[/tex], solve for [tex]x[/tex] and identify if it is an extraneous solution.

A. [tex]x = 4[/tex], solution is extraneous
B. [tex]x = 4[/tex], solution is not extraneous
C. [tex]x = 5[/tex], solution is extraneous
D. [tex]x = 5[/tex], solution is not extraneous



Answer :

To solve the equation [tex]\(\sqrt{2x + 1} = 3\)[/tex] for [tex]\(x\)[/tex], we need to follow these steps:

1. Square both sides of the equation to eliminate the square root. Remember that squaring is a reversible operation, but it can introduce extraneous solutions, so we need to verify our answers later.

[tex]\[ (\sqrt{2x + 1})^2 = 3^2 \][/tex]

This simplifies to:

[tex]\[ 2x + 1 = 9 \][/tex]

2. Solve the resulting linear equation for [tex]\(x\)[/tex].

[tex]\[ 2x + 1 = 9 \][/tex]

Subtract 1 from both sides:

[tex]\[ 2x = 8 \][/tex]

Divide both sides by 2:

[tex]\[ x = 4 \][/tex]

3. Verify the solution by substituting [tex]\(x = 4\)[/tex] back into the original equation to check if it holds true.

Substituting [tex]\(x = 4\)[/tex] into [tex]\(\sqrt{2x + 1}\)[/tex]:

[tex]\[ \sqrt{2(4) + 1} = \sqrt{8 + 1} = \sqrt{9} = 3 \][/tex]

Since the left-hand side (LHS) is equal to the right-hand side (RHS):

[tex]\[ 3 = 3 \][/tex]

The solution [tex]\(x = 4\)[/tex] satisfies the original equation.

Since [tex]\(x = 4\)[/tex] satisfies the original equation [tex]\(\sqrt{2x + 1} = 3\)[/tex], it is not an extraneous solution.

So, the correct answer is:

[tex]\(x = 4\)[/tex], solution is not extraneous.

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