If a and β are the roots of the equation
ax2+bx+c=0, then roots of
ax2−bx(x−1)+c(x−1)2=0
are
1α,1β
1α,β
α1+α,β1+β
α,1β
We can write (1) as
a−xx−12+b−xx−1+c=0⇒ −xx−1=α,β⇒x=α1+α,β1+β