SOLUTION: Solve the equation x -2 squareroot x = 8

Algebra ->  College  -> Linear Algebra -> SOLUTION: Solve the equation x -2 squareroot x = 8      Log On


   

Question 180047: Solve the equation x -2 squareroot x = 8
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
x-2sqrt%28x%29=8
:
-2sqrt%28x%29=8-xsubtracted x from both sides
:
4x=%288-x%29%5E2squared both sides
:
4x=64-16x%2Bx%5E2
:
x%5E2-20x%2B64=0
:
%28x-16%29%28x-4%29=0
:
x=4 and 16
:
4 is an extraneous root which occurs at times when squaring, so we throw it out as a solution
:
x=16