Question 184641
18x^2 + 9x +1 = 0
;
they used the quadratic formula, namely: 
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
;
In your equation a=18, b=9, c=1, so we have:
{{{x = (-9 +- sqrt( 9^2 - 4 * 18 * 1 ))/(2*18) }}}
:
{{{x = (-9 +- sqrt(81 - 72 ))/(36) }}}
:
{{{x = (-9 +- sqrt(9))/(36) }}}
Two solutions;
{{{x = (-9 + 3)/(36) }}}
x = {{{(-6)/36}}}
x = {{{-1/6}}}
and
{{{x = (-9 - 3)/(36) }}}
x = {{{(-12)/36}}}
x = {{{-1/3}}}
:
:
Could you follow this OK?