x=(-b+-sqrt b^2-4ac)/2a
a=1, b=-4, c=10. Plug these in:
x=(4+-sqrt 16-4(1)(10)/(2)(1))
x=(4+-sqrt(16-40)/2)
x=(4+-sqrt(-24)/2)
sqrt(-24)=2i*sqrt(6)
x=(4+-2i*sqrt6)/(2)...divide this by 2, and your final answers are:
x=2+i*sqrt(6), x=2-i*sqrt(6)
Sorry for not using symbols...solving this on my phone. Hope it makes sense :)