SOLUTION: Please help me solve this equation:{{{ x= sqrt ( x+20 ) }}}. what i have tried is squaring both sides to where i get{{{ x^2=x+20 }}} the i subtracted the {{{ x^2-x=20 }}} the

Algebra ->  Radicals -> SOLUTION: Please help me solve this equation:{{{ x= sqrt ( x+20 ) }}}. what i have tried is squaring both sides to where i get{{{ x^2=x+20 }}} the i subtracted the {{{ x^2-x=20 }}} the      Log On


   

Question 566930: Please help me solve this equation:+x=++sqrt+%28+x%2B20+%29+.
what i have tried is squaring both sides to where i get+x%5E2=x%2B20+
the i subtracted the +x%5E2-x=20+
the answer i got was +x=20+ but my teacher said it was wrong
he has said the correct answer is +x=13%2F12+ what did i do wrong?
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
How'd you get x=20 from x^2 - x = 20?

You should also subtract the 20, so your equation will look something like

, this factors to

, so x = 5 or x = -4. Since we have a square root, we should check to make sure our solutions actually work. x = 5 definitely works, x = -4 probably won't since the square root usually denotes only the positive root. The solution 13/12 is wrong.