Factorising Quadratic Expressions (Leaving Cert Mathematics): Flashcards

$ax^2 + bx + c$ where $a \neq 0$

2

Rewriting as product of simpler expressions

$(x + y)(x - y)$

When terms have common factors, e.g., $ax^2 + bx$

1, 4, 9, 16, 25... (i.e., $1^2, 2^2, 3^2...$)

$x(x - 5)$

$(x + 5)(x - 5)$

$(3x + 4y)(3x - 4y)$

Expand brackets to get original expression

Look for common factors first

$(x + 5)(x + 2)$