Chapter: Quadratic Equations· Mathematics Part 1 (Algebra)
Answer: \(x = 4\) or \(x = -5\)
Product \(ac = -20\), sum \(b = 1\). The numbers are \(+5\) and \(-4\).
\(x^2 + 5x - 4x - 20 = 0\)
\(x(x + 5) - 4(x + 5) = 0\)
\((x + 5)(x - 4) = 0\)
\(\therefore x + 5 = 0\) or \(x - 4 = 0\)
\(\therefore x = -5\) or \(x = 4\)
(June 2026 asked \(25m^2 = 9\): \(25m^2 - 9 = (5m + 3)(5m - 3) = 0\), so \(m = \pm\dfrac{3}{5}\).)