If α, β are roots of the equation 
, then write the value of 
.
given x2-a(x+1)-c=0
x2-ax-a-c=0
x2-ax-(a+c)=0
as α, β are roots of equation, we get
sum of the roots α + β = a
Product of roots αβ = - (a + c)
Given (1+ α) (1+ β)
= 1 + (α + β) + (α β)
= 1 + a – a – c
= 1 – c.
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