Call

α + β = - 3 .......(1)

and αβ = \(\frac{-5}{2}\) .........(2)

(α - β)2 = (α + β)2 - 4αβ 

= (-3)2 - 4 x \(\frac{-5}{2}\)

= 9 + 10

= 19

α - β = ±√19 ........(3)

By adding equations (1) and (3), we get

2α = - 3 ± √19

∴ α = \(\frac{- 3 ± \sqrt{19}}{2}\)

By subtracting equation (3) from (1), we get

2β =  \(\frac{- 3\,\mp\,\sqrt{19}}{2}\)

⇒ β = \(\frac{- 3\,\mp\,\sqrt{19}}{2}\)

Hence,

Either  α = \(\frac{- 3 + \sqrt{19}}{2}\) , β = \(\frac{- 3 - \sqrt{19}}{2}\)

Or, α = \(\frac{- 3 - \sqrt{19}}{2}\),  β = \(\frac{- 3 + \sqrt{19}}{2}\)