a) What is the solution to the equation?
b) What is the extraneous solution? Why?
c) In general, what is an extraneous solution?
(please show all work, this genuinely helps me understand how you got to the answer, thank you in advance!)
Equation is \(x+2={\sqrt{3x+10}}\)
a) First of all, squaring both sides
\((x+2)^2=3x+10\)
\(x^2+4x+4=3x+10\)
\(x^2+x-6=0\)
⇒ \(x^2+3x-2x-6=0\)
\((x+3)(x-2)=0\)
∴ x = -3 or 2
b) Here we can't have \({\sqrt{3x+10}}<0\)
∵ Any value \(x<{-10 \over 3}\) is extraneous.
∴ Squaring both sides in \({\sqrt {3x+10}}=x\)
\(3x+10=x^2\)
\(x^2-3x-10=0\)
⇒ \((x-5)(x+2)=0 \)
\(x=5\) or \(-2\)
1st case : Putting x=5 in eq. 2nd case: Putting x=-2 in eq.
\({\sqrt{3(5)+10}} = 5\) \({\sqrt{3(-2)+10}}=(-2)^2\)
⇒ \(5=5\) ⇒ \(2≠-2\)
∴ x = 5 is the extraneous solution.
c) An extraneous solution is a solution that's evolved from the process of solving of the equation but its not a valid solution to the equation. You know, they are those "extra answers" that we get while solving the problem and they may not necessarily be valid
~Roll the credits