Chapter 11 - Rational Expressions and Functions - 11-4 Adding and Subtracting Rational Expressions - Standardized Test Prep - Page 677: 56

$x = 13.18$ cm

$200 = x*x+4*x*.5$ $200 = x^2 +2x$ $x^2+2x-200=0$ $x=(-b±\sqrt {b^2-4ac})/2a$ $x = (-(2)±\sqrt {2^2-4*1*-200})/2*1$ $x = (-2 ± \sqrt{4+800})/2$ $x = (-2 ± \sqrt{804})/2$ $x = (-2 ± 2\sqrt{201})/2$ $x = (-1 ± \sqrt{201})$ $x= -1 ± 14.1774$ $x = -1+14.1774 = 13.1774$ $x = -1 - 14.1774 = -15.1774$ (we can't have a negative distance, so this value is invalid)