Question 343890
{{{2x(x+1)=7}}}
{{{2x^2+2x-7=0}}}
Use the quadratic formula,
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
{{{x = (-2 +- sqrt( 2^2-4*2*(-7) ))/(2*2) }}} 
{{{x = (-2 +- sqrt( 4+56))/4 }}}
{{{x = (-2 +- sqrt( 60 ))/4 }}}  
{{{x = (-2 +- 2sqrt( 15 ))/4 }}}
  {{{highlight(x = (-1 +- sqrt( 15 ))/2) }}}