Quadratic equations

A quadratic equation can have two solutions, and factorising is your first tool in Grade 10.

• Write it in standard form ax² + bx + c = 0 BEFORE factorising.
• Factorise, then use the zero-product rule: if A·B = 0 then A = 0 or B = 0.
• Never divide both sides by x — you will lose the solution x = 0.
• Check both roots make sense in the context of the problem.

• Standard form — everything moved to one side, equal to zero.
• Zero-product rule — a product is zero only when a factor is zero.