Question 74861
I'm assuming the equation looks like this: 
{{{4x^2-8x+3=5}}}
{{{4x^2-8x+3-5=cross(5-5)}}}Subtract 5 from both sides
{{{4x^2-8x-2=0}}}Plug this into the quadratic formula
*[invoke quadratic "x", 4, -8, -2 ]
In other words, you should get
{{{x=(8+sqrt(96))/8}}} and {{{x=(8-sqrt(96))/8}}}
Which reduces to
{{{x=1+(sqrt(6))/2}}} and {{{x=1-(sqrt(6))/2}}}
You were close to the answer, so double check your steps to see where you went wrong.