If alpha and beta are the roots of the equation ax2 bx c 0 then the value of ........

Quantitative Aptitude (CDS) Quadratic Equations

If α and β are the roots of the equation ax² + bx + c = 0, then the value of

$\frac{1}{a\alpha +b}+\frac{1}{a\beta +b} \: is$

a/bc

b/ac

c/ab

1/abc

As α & β are roots of equation

$ax^{2}+bx+c=0$

then

$\alpha+\beta= -b/a$

$\alpha\beta= -c/a$

From given equation

$\frac{1}{a\alpha +b}+\frac{1}{a\beta +b}$

$= [ (a\beta+b)+(a\alpha+b)] / [ (a\beta+b)(a\alpha+b)]$

Solving we get b/ac

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