2014 · Q14
In solving a problem, one student makes a mistake in the coefficient of the first degree term and obtains -9 and -1 for the roots. Another student makes a mistake in the constant term of the equation and obtains 8 and 2 for the roots. The correct equation was
Elementary MathematicsAlgebra
- Ax^2 + 10x + 9 = 0
- Bx^2 - 10x + 16 = 0
- Cx^2 - 10x + 9 = 0
- DNone of the above
Explanation
Product of roots = (-9)(-1) = 9 (constant term right); sum = 8 + 2 = 10 (first-degree coefficient right): x^2 - 10x + 9 = 0.