Question 134936
Given : {{{x^2+y^2=16}}}
{{{4x^2-9y^2=36 }}}
{{{9x^2+9y^2=144}}}
Add these two
{{{13x^2    = 180}}}
{{{ x^2 = (180/13)}}}
{{{ x = sqrt(180/13)}}}
{{{ x = (sqrt(180)*sqrt(13))/13)}}}
{{{ x = (sqrt(36)*sqrt(5)*sqrt(13))/13)}}}
{{{ x = (6*sqrt(5)*sqrt(13))/13)}}}
{{{ x = (6*sqrt(65))/13)}}}