©G Dear 2008 – Not to be sold/Free to use Mathematic (Preliminary) Basic Arithmetic Factors Grouping in Pairs Stage 6 - Year 11 Press Ctrl-A ©G Dear 2008 – Not to be sold/Free to use

a is common to both terms and can be put in front of brackets. Factorisation Simple Factors ax + ay = a( )     a is common to both terms and can be put in front of brackets.

x+y remains when the a is removed and are placed inside the brackets. Factorisation Simple Factors ax + ay = a(x + y)      x+y remains when the a is removed and are placed inside the brackets. Example 15x - 24y = 3 x 5x - 3 x 8y = 3(5x - 8y)

ax + ay + bx + by = a(x + y) + b(x + y) Factorisation Grouping in Pairs ax + ay + bx + by = a(x + y) + b(x + y) Examples 3x2 + x + 12x + 4 = (3x2 + x) + (12x + 4) = x(3x + 1) + 4(3x + 1)  Note: 3x + 1 is the common factor = (3x + 1)(x + 4)