EQ011 · Equations & inequalities · Classes 10–11
Factor method for quadratics
To solve a quadratic by factorising, write it as a product equal to 0. A product is 0 only if a factor is 0, which gives the roots.
(x − 2)(x − 3) = 0Factor method for quadratics
📐 Formula
(x − p)(x − q) = 0 ⇒ x = p or x = q
✏️ Worked example
x² − 5x + 6 = 0 ⇒ (x − 2)(x − 3) = 0 ⇒ x = 2 or x = 3.
🌍 Where it is used
Quick solutions when the numbers are friendly.
❓ Quick check
Roots of (x + 4)(x − 1) = 0?
🏋️ Practice
EasySolve x² − 9 = 0.
Answer: x = ±3
MediumSolve x² + 7x + 12 = 0.
Answer: x = −3 or −4
ChallengeSolve x² = 5x.
Answer: x = 0 or 5