Question 184643
{{{4x^2 - 8x - 5 = 0}}}
Use the quadratic formula:
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
where {{{ax^2 + bx + c = 0}}}
{{{a = 4}}}
{{{b = -8}}}
{{{c = -5}}}
{{{x = (-(-8) +- sqrt( (-8)^2-4*4*(-5) ))/(2*4) }}}
{{{x = (8 +- sqrt(64 + 80 ))/8 }}}
{{{x = (8 +- sqrt( 144 ))/8 }}}
{{{x = (8 +- 12)/8 }}}
{{{x = (8 + 12)/8 }}}
{{{x = 20/8}}}
{{{x = 5/2}}}
and
{{{x = (8 - 12)/8 }}}
{{{x = (-4)/8}}}
{{{x = -(1/2)}}}