This section covers Quadratic Equations.
In algebra, any expression of the form ax2 + bx + c where a ≠ 0 is called a quadratic expression.
It is useful to remember these results of expanding brackets:
(x + a)2 = x2 + 2ax + a2
(x - a)2 = x2 – 2ax + a2
(x + a)(x – a) = x2 – a2
Equations of the form ax2 + bx + c = 0, where a ≠ 0 are quadratic equations.
Some quadratic equations can be solved by factorising the quadratic expression.