1. A, b and c can be any numbers
Factorising a Quadratic Equation
16 November 2004
All of these equations are quadratic equations:
y = x2 + 5x + 6
y = x2 + 3x - 10
y = x2 - 16
y = x2 + 3x
y = ax2 + bx + c
A, b and c can be any numbers

2. 0 = x2 + 5x + 6 1 X 6 = 6 2 X 3 = 6 2 + 3 = 5 0 = (x + 2)(x + 3)
To solve by factorising
0 = x2 + 5x + 6
FIRST Find all the factor pairs of 6
1 X 6 = 6
2 X 3 = 6
SECOND Choose the pair that add up to 5
2 + 3 = 5
THIRD These two numbers give the answer like this:
0 = (x + 2)(x + 3)
x = -2 and -3