# How do you solve for x in sqrt(42-x)+x =13?

Feb 7, 2015

Okay start by

Rewriting equation as $\sqrt{42 - x} = 13 - x$

Now square both sides

So we are left with the equation  42 - x = (13 - x)^2 = x^2− 26x +169

Next step bring all the terms to one side of the equation
SO ${x}^{2} - 26 x + 169 - 42 + x = 0$

So using the quadratic formula i get that The values of x are = $x = 17.908326913195985 , 7.091673086804016$