The common root of the equation x2 – bx + c = 0 and x2 + bx – a = 0 is

Given: Two Quadratic Equations and

Required: to find the common root of the given Quadratic Equations


Let the common root be α


Α is the root of x2–bx + c = 0


x2–bx + c = 0


α2–bα + c = 0 -eq(1)


Also, α is the root of x2 + bx–a = 0


α2 + bα–a = 0 -eq(2)


Here, eq(1) = eq(2)


α2 + bα–a = α2–bα + c


2bα = c + a


α =


The common root is α =


Correct Option is - Option(A)

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