Quadratics
Null Factor Law
Quadratics
Factorising when A = 0 Factorising when A ≠ 0 Factorising special situations

Solving quadratic equations

When the product of two or more numbers is zero, then at least one of them must equal zero for this to be true.
\[\mathrm{If} \quad A\cdot B=0 \quad \mathrm{then\ either} \quad A=0\quad \mathrm{or}\quad B=0\]
\[\mathrm{If} \quad A\cdot B=0 \quad \mathrm{then\ either} \quad A=0\quad \mathrm{or}\quad B=0\]