x²-√13 mx+3m²=0
x²-√13 mx=-3m²
x²- √13 mx+(√13/2m)²=-3m²+13/4m²
(x-√13/2m)²=1/4m²
x-√13/2m=±1/2m
x=√13/2m±1/2m
x=(√13±1)m/2