Question

If the quadratic equations x² + ax + b = 0 and x² + bx + a = 0 (a ≠ b) have a common root, then the numerical value of a + b is... . 

Answer 1

Given equations are x² + ax + b = O and x² + bx+ a = 0 have common root On subtracting above equations, 

we get (a - b)x + (b - a) = 0

⇒ x = 1