We have, x4−10x3+37x2−60x+36=0
since, α,α,β,β are the roots of the above equation. ∴α+α+β+β=1−(−10)=10 ⇒α+β=5 ...(i)
and (α)(α)(β)(β)=136 ⇒α2β2=36 ⇒αβ=6 ...(ii)
From Eqs. (i) and (ii), we have α(5−α)=6 ⇒α2−5α+6=0 ⇒α=2,3 ⇒β=3,2
Since α<β, hence α=2,β=3 ∴2α+3β−2αβ =2×2+3×3−2×2×3 =4+9−12=1