2014 · Q45
If m and n (m > n) are the roots of the equation 7(x + 2a)² + 3a² = 5a(7x + 23a), where a > 0, then what is 3m − n equal to?
Elementary MathematicsAlgebra
- A12a
- B14a
- C15a
- D18a
Explanation
The equation reduces to x² − ax − 12a² = 0, roots 4a and −3a; 3(4a) − (−3a) = 15a.