Given the equation −4 * sqrt (x-3) = 12, solve for x and identify if it is an extraneous solution.
4*sqrt(x-3)= 12. On squarng both the sides, we get, 16.(x-3) =144. or (x-3)= 144/16 = 9 or we can say that x = 3+9 = 12. Thus, x = 12 and it is not an extraneous solution. It would have been extraneous if x would have been 3.
Answer:
Given the equation: \(-4\sqrt{x-3}=12\) .....[1]
Solve for x;
Divide both sides by -4 in [1]; we get;
\(\sqrt{x-3} = -3\)
Squaring both the sides we get;
\(x-3 = (-3)^2\)
or
\(x -3 = 9\)
Add 3 both sides we get;
\(x -3+3= 9+3\)
Simplify:
x= 12
Extraneous solution states that it is a root of a transformed equation that is not a root of the original equation because it was excluded from the domain of the original equation.
Substitute x= 12 in [1]
\(-4\sqrt{12-3}=12\)
\(-4\sqrt{9}=12\)
\(-4\cdot 3=12\)
\(-12 =12\) False.
Therefore, the value of x is 12 and it is an extraneous solution.