Question

Solve the following equations for x. Identify any extraneous solutions. Show all work.
-4 sqrt(x+9)=20

I think what I did was wrong.
I got x=567

Answer 1

\[-4\sqrt{x+9}=20\]

Answer 2

-4*sqrt(x+9) = 20

Divide both sides by -4 and you get:

sqrt(x + 9) = -5

Then square both sides and you get

X + 9 = 25

Minus 9 from both sides and you get:

x = 16

Then test 16.

-4*sqrt(16+9) = 20

-4*5 = -20

I believe x = 16 is an extraneous root.

Answer 3

-4 * 5 = -20 which is not equal to 20, thats why I think x =16 is an extraneous root.

Answer 4

thanks