← LearnYear 9 Maths · AlgebraFree placement check
Year 9AC9M9A02
Summary of important concepts

Expanding — FOIL

Simplify algebraic expressions, expand binomial products and factorise monic quadratic expressions.

First, Outer, Inner, Last. Work in the same order every time and nothing gets missed.

Worked example

e.g. (x+2)(3x−4)(x+2)(3x-4)
  1. Multiply the First term of each bracket3x23x^{2}
  2. Multiply the Outer terms3x2−4x3x^{2} - 4x
  3. Multiply the Inner terms3x2−4x+6x3x^{2} - 4x + 6x
  4. Multiply the Last term of each bracket3x2−4x+6x−83x^{2} - 4x + 6x - 8
  5. Group like terms3x2+2x−83x^{2} + 2x - 8

Practice

1
(x+3)(x+5)(x+3)(x+5)
Answerx2+8x+15x^{2} + 8x + 15
2
(x−4)(x+7)(x-4)(x+7)
Answerx2+3x−28x^{2} + 3x - 28
3
(2x+1)(x−6)(2x+1)(x-6)
Answer2x2−11x−62x^{2} - 11x - 6
4
(3x−2)(2x+5)(3x-2)(2x+5)
Answer6x2+11x−106x^{2} + 11x - 10
5
(x−9)(x−2)(x-9)(x-2)
Answerx2−11x+18x^{2} - 11x + 18
6
(4x+3)(4x−3)(4x+3)(4x-3)
Answer16x2−916x^{2} - 9
7
(5x−1)(x+4)(5x-1)(x+4)
Answer5x2+19x−45x^{2} + 19x - 4
8
(2x−7)(3x−1)(2x-7)(3x-1)
Answer6x2−23x+76x^{2} - 23x + 7
Next step
Practise Expanding — FOIL with instant marking
A free 10-minute placement check finds which Year 9 topics to work on first, then Summit builds a weekly plan around them.
See where my child is →