SOLUTION: Please help me find the roots of: {{{sqrt(sqrt(x+5)+x)=5}}}

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Question 475331: Please help me find the roots of:
sqrt%28sqrt%28x%2B5%29%2Bx%29=5
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
sqrt%28sqrt%28x%2B5%29%2Bx%29=5
:
Square both sides
sqrt%28x%2B5%29%2Bx=25
:
subtract x from both sides
sqrt%28x%2B5%29=25-x
:
Square both sides again
x + 5 = (25-x)^2
:
FOIL (25-x)(25-x)
x + 5 = 625 - 50x + x^2
:
Combine as a quadratic equation
x^2 - 50x - x + 625 - 5 = 0
x^2 - 51x + 620 = 0
You can use the quadratic formula to solve this; a=1, b=-51,c=620, but
this will factor to:
(x-20)(x-31) = 0
Two solutions
x = 20
x = 31
;
:
Try both solutions in the original equation, only x=20 will work