Question 581080
The quadratic formula is:
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
It applies to the general quadratic equation:
{{{ ax^2 + bx + c = 0}}}
You can see there is a " +- " before the 
square root sign. That means there are 2 solutions:
{{{x[1] = (-b + sqrt( b^2-4*a*c ))/(2*a) }}}
and
{{{x[2] = (-b - sqrt( b^2-4*a*c ))/(2*a) }}}
If the {{{ sqrt( b^2-4*a*c ) }}} term is zero,
then {{{ x[1] = x[2] }}} and there is 1 solution
but if this term is positive, then {{{ x[1] }}}
and {{{ x[2] }}} are different and there will be 2 solutions
Hope this helps