Question

Find the solution of 3 square root x+5=-9, and determine if it is an extraneous solution.

The options are:
X=4; not extraneous
X=4; extraneous
X=0; extraneous
X=0; not extraneous

Answer 1

so... ok.. what do you get for "x" from \(\bf 3\sqrt{x+5}=-9\)?

Answer 2

X=4; extraneous ?

Answer 3

@jdoe0001

Answer 4

is it? what makes you think so?

Answer 5

well, notice \(\bf 3\sqrt{{\color{brown}{ x}}+5}=-9\implies 3\sqrt{{\color{brown}{ 4}}+5}=-9\implies 3\cdot \sqrt{9}=-9
\\ \quad \\
3\cdot 3\ne -9\)

thus, if x = 4, it IS extraneous

Answer 6

even though x = 4 is correct, procedure wise

Answer 7

I subtracted 5 which got 4. But how do you determine if it is extraneous?