Find expert answers and community support for all your questions on IDNLearn.com. Ask your questions and receive reliable and comprehensive answers from our dedicated community of professionals.

Which of the following is an extraneous solution of [tex]\((45-3x)^{\frac{1}{2}} = x - 9\)[/tex]?

A. [tex]\(x = -12\)[/tex]
B. [tex]\(x = -3\)[/tex]
C. [tex]\(x = 3\)[/tex]
D. [tex]\(x = 12\)[/tex]


Sagot :

To determine which of the given values is an extraneous solution of the equation [tex]\((45 - 3x)^{\frac{1}{2}} = x - 9\)[/tex], we need to verify each value in two steps. Let's check if substituting the value satisfies the original equation and if it is a valid solution.

### Step-by-Step Solution

1. Check [tex]\( x = -12 \)[/tex]:
[tex]\[ (45 - 3(-12))^{\frac{1}{2}} = (-12) - 9 \][/tex]
Simplify inside the square root:
[tex]\[ (45 + 36)^{\frac{1}{2}} = -21 \][/tex]
[tex]\[ 81^{\frac{1}{2}} = -21 \][/tex]
[tex]\[ 9 = -21 \][/tex]
This is not true, so [tex]\( x = -12 \)[/tex] is not a solution.

2. Check [tex]\( x = -3 \)[/tex]:
[tex]\[ (45 - 3(-3))^{\frac{1}{2}} = (-3) - 9 \][/tex]
Simplify inside the square root:
[tex]\[ (45 + 9)^{\frac{1}{2}} = -12 \][/tex]
[tex]\[ 54^{\frac{1}{2}} = -12 \][/tex]
[tex]\[ \sqrt{54} \approx 7.35 \neq -12 \][/tex]
This is not true, so [tex]\( x = -3 \)[/tex] is not a solution.

3. Check [tex]\( x = 3 \)[/tex]:
[tex]\[ (45 - 3(3))^{\frac{1}{2}} = 3 - 9 \][/tex]
Simplify inside the square root:
[tex]\[ (45 - 9)^{\frac{1}{2}} = -6 \][/tex]
[tex]\[ 36^{\frac{1}{2}} = -6 \][/tex]
[tex]\[ 6 \neq -6 \][/tex]
This is not true, so [tex]\( x = 3 \)[/tex] is not a solution.

4. Check [tex]\( x = 12 \)[/tex]:
[tex]\[ (45 - 3(12))^{\frac{1}{2}} = 12 - 9 \][/tex]
Simplify inside the square root:
[tex]\[ (45 - 36)^{\frac{1}{2}} = 3 \][/tex]
[tex]\[ 9^{\frac{1}{2}} = 3 \][/tex]
[tex]\[ 3 = 3 \][/tex]
This is true, so [tex]\( x = 12 \)[/tex] is a valid solution.

### Conclusion

After checking all the provided values, none of the given options yield extraneous solutions because each value correctly identifies whether it is a solution or not. The extraneous solutions list is empty, which means none of the given values add an extra root that falsely satisfies the equation.

Thus, none of [tex]\(x = -12\)[/tex], [tex]\(x = -3\)[/tex], [tex]\(x = 3\)[/tex], nor [tex]\(x = 12\)[/tex] are extraneous solutions for the given equation.