CMA Foundation · Fundamentals of Business Mathematics and Statistics · Quadratic Equations
If the roots of the quadratic equation 2x² - 10x + 7 = 0 are α and β, what is the value of α + β?
The sum of the roots is 5. For a quadratic ax² + bx + c = 0 the sum equals -b/a, which here is -(-10)/2 = 5. The value 3.5 is the product of the roots, and -5 results from ignoring the sign.
- A5Correct
- B-5
- C3.5
- D-3.5
Explanation
For ax² + bx + c = 0, the sum of roots = -b/a = -(-10)/2 = 5. Option -5 comes from forgetting the sign change on b, and 3.5 is the product c/a, not the sum.
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