SOLUTION: Can someone explain the steps to me for solving this equation? x- sqrt 15-2x = 0 the solution set is??

Algebra ->  Square-cubic-other-roots -> SOLUTION: Can someone explain the steps to me for solving this equation? x- sqrt 15-2x = 0 the solution set is??      Log On


   

Question 262567: Can someone explain the steps to me for solving this equation?
x- sqrt 15-2x = 0
the solution set is??
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Can someone explain the steps to me for solving this equation?
x- sqrt 15-2x = 0
Assume the problem is
x+-+sqrt%2815-2x%29+=+0
:
Add sqrt%2815-2x%29 to both sides
:
x+=+sqrt%2815-2x%29
:
Squaring both sides gets rid of the radical
x^2 = 15 - 2x
:
Arrange as a quadratic equation
x^2 + 2x - 15 = 0
:
Factors to
(x+5)(x-3) = 0
:
Two solutions
x = -5
and
x = +3,
:
Check solutions in original equation
x = 3
3+-+sqrt%2815-2%283%29%29+=+0
3+-+sqrt%2815-6%29+=+0
3+-+sqrt%289%29+=+0
3 - 3 = 0; a good solution
:
however when x = -5
-5+-+sqrt%2815-2%28-5%29%29+=+0
-5+-+sqrt%2815%2B10%29+=+0
-5+-+sqrt%2825%29+=+0
-5 - 5 does not = 0, not a solution