Question 731275
Minus signs always cause problems.
They are hard to see, easy to miss, and likely to change as you copy an equation to the next line, or to another page.
Then you need someone else to look for your mistake, because it is invisible to you.
You were doing OK all the way to
{{{4x^2-2x-2x+1=33+x^2}}}
From there you should have added a {{{-x^2}}} to both sides to get
{{{3x^2-4x-32=0}}} (You got {{{5x^2-4x-32=0}}} instead).
Applying the quadratic formula to {{{3x^2-4x-32=0}}} with {{{a=3}}} , {{{b=-4}}} and {{{c=-32}}} you would get
{{{x = (4 +- sqrt(16+384))/6 }}} --> {{{x = (4 +- sqrt(400))/6 }}} --> {{{x = (4 +- 20)/6 }}}
That would give you the solutions
{{{x=(4+20)/6=24/6=4}}} and {{{x=(4-20)/6=-16/6=-8/3}}}