Question 749920
<pre>
&#8730;b/a-x= &#8730;a

{{{sqrt(b/(a-x))}}}{{{""=""}}}{{{sqrt(a)}}}

Square both sides:

{{{(sqrt(b/(a-x)))^2}}}{{{""=""}}}{{{(sqrt(a))^2}}}

When you square both sides you take away the
radical:

{{{(b/(a-x))}}}{{{""=""}}}{{{a}}}

Multiply both sides by (a-x)

{{{(b/(a-x))}}}{{{""*""}}}{{{(a-x)}}}{{{""=""}}}{{{a}}}{{{""*""}}}{{{(a-x)}}}

Cancel on the left.  Distribute on the right

{{{(b/(cross(a-x)))}}}{{{""*""}}}{{{(cross(a-x))}}}{{{""=""}}}{{{a^2}}}{{{""-""}}}{{{a*x)}}}

      b = a² - a·x

Add a·x to both sides:

b + a·x = a²

Subtract b from both sides:

    a·x = a² - b

Divide both sides by a:

   {{{(a*x)/a}}}{{{""=""}}}{{{(a^2-b)/a}}}

Cancel the a's on the left

   {{{(cross(a)*x)/cross(a)}}}{{{""=""}}}{{{(a^2-b)/a}}}

   x = {{{(a^2-b)/a}}}

Edwin</pre>