passwella.
Menu

JAMB Mathematics 1981 Question 47

Question 47

Quadratic Equations

The sum of the root of a quadratic equation is 5/2 and the product of its roots is 4. The quadratic equation is

  1. A.2x2 + 5x + 8 = 0
  2. B.2x2 − 5x + 8 = 0
  3. C.2x2 − 8x + 5 = 0
  4. D.2x2 + 8x − 5 = 0
  5. E.2x2 − 5x − 8 = 0.
Show the answer and explanation

Answer: B (2x2 − 5x + 8 = 0)

Explanation

x² − (sum)x + (product) = 0 gives x² − 5x/2 + 4 = 0, i.e. 2x² − 5x + 8 = 0.