How do you solve $sqrt(x+20)-x=0$ ?

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Answer 1 · 2016-04-12T19:28:42

$x={-4,5}$

$sqrt(x+20)-x=0$

$sqrt(x+20)=x$

$(sqrt(x+20))^2=x^2$

$x+20=x^2$

$x^2-x-20=0$

$(x-5)(x+4)=0$

$if (x-5)=0" then "x=5$

$if (x+4)=0" then "x=-4$

$x={-4,5}$

How do you solve sqrt(x+20)-x=0sqrt(x+20)-x=0?