IDNLearn.com provides a user-friendly platform for finding and sharing knowledge. Our community is here to provide the comprehensive and accurate answers you need to make informed decisions.

Li Juan solves the equation below by first squaring both sides of the equation. [tex]\sqrt{3-2w}=w+6[/tex]
What extraneous solution does Li Juan obtain?


Sagot :

Answer:

w = -11

Step-by-step explanation:

[tex]\sqrt{3 - 2w} = w + 6[/tex]

[tex](\sqrt{3 - 2w})^2 = (w + 6)^2[/tex]

[tex] 3 - 2w = w^2 + 12w + 36 [/tex]

[tex] w^2 + 14w + 33 = 0 [/tex]

[tex] (w + 11)(w + 3) = 0 [/tex]

[tex] w + 11 = 0 [/tex]   or   [tex] w + 3 = 0 [/tex]

[tex] w = -11 [/tex]   or   [tex] w = -3 [/tex]

When you square both sides of an equation, you must check all solutions for extraneous solutions.

Check w = -11.

[tex]\sqrt{3 - 2w} = w + 6[/tex]

[tex] \sqrt{3 - 2(-11)} = -11 + 6 [/tex]

[tex] \sqrt{3 + 22} = -5 [/tex]

[tex] \sqrt{25} = -5 [/tex]

[tex] 5 = -5 [/tex]

This is a false statement, so the solution w = -11 is extraneous since it does not satisfy the original equation.

Check w = -3.

[tex]\sqrt{3 - 2w} = w + 6[/tex]

[tex] \sqrt{3 - 2(-3)} = -3 + 6 [/tex]

[tex] \sqrt{3 + 6} = 3 [/tex]

[tex] \sqrt{9} = 3 [/tex]

[tex] 3 = 3 [/tex]

This is a true statement, so the solution w = -3 is valid.

Answer: w = -11