Question 625481

We have to solve: {{{ x^2+x-1=0 }}}

(a = 1, b = 1, c = -1)

{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 

{{{x = (-1 +- sqrt( 1^2-4*1*(-1) ))/(2*1) }}} 

{{{x = (-1 +- sqrt( 5 ))/2 }}} 

Answer: {{{x = (-1 + sqrt( 5 ))/2 }}} , {{{x = (-1 - sqrt( 5 ))/2 }}}


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