📐 Algebra & Equations
Algebra is the highest-weightage topic in E-Math, appearing in both papers and forming the foundation for many other topics including graphs, trigonometry, and statistics. You must master algebraic manipulation, factorisation, quadratic equations, simultaneous equations, algebraic fractions, and inequalities. This chapter provides comprehensive coverage with multiple worked examples for every key technique.
Algebraic fluency is what separates A1 students from the rest. Many students understand the concepts but lose marks because they make errors during manipulation. The key to mastery is practice — work through every example in this chapter, then attempt past paper questions until the techniques become second nature.
Algebraic Expansion & Identities
Expansion means removing brackets by multiplying each term inside the bracket by the term outside. For two binomials, use the FOIL method (First, Outer, Inner, Last) or the grid method. However, the three special algebraic identities below are so commonly used that you should memorise them and apply them directly — this saves time and reduces errors.
Perfect Square (Sum)
(a + b)^2 = a^2 + 2ab + b^2Perfect Square (Difference)
(a - b)^2 = a^2 - 2ab + b^2Difference of Two Squares
(a + b)(a - b) = a^2 - b^2The most common mistake with perfect squares is forgetting the middle term. Students write (a + b)^2 = a^2 + b^2, which is WRONG. The correct expansion always has the middle term 2ab. Always check your expansion by counting terms: a perfect square expansion should have 3 terms.
🧮Algebraic Expansion & Factorisation
Special algebraic identities tested frequently in Paper 1. Must be able to expand and factorise fluently.
a^2 - b^2 = (a + b)(a - b)a^2 + 2ab + b^2 = (a + b)^2a^2 - 2ab + b^2 = (a - b)^2ax^2 + bx + c = (px + q)(rx + s) \text{ where } pr = a,\, qs = c,\, ps + qr = b(a + b)(c + d) = ac + ad + bc + bd(a + b)^3 = a^3 + 3a^2b + 3ab^2 + b^3📝Worked Example 1: Using Algebraic Identities
Expand and simplify (3x + 2)^2 - (3x + 2)(3x - 2).
📝Worked Example 2: Expanding Three Brackets
Expand (x + 1)(x - 2)(x + 3).
What the full chapter covers
Algebraic Expansion & Identities
Factorisation
Algebraic Fractions
Quadratic Equations — 3 Methods
Method 1: Factorisation
Method 2: Quadratic Formula
Method 3: Completing the Square
Simultaneous Equations
Inequalities
Changing the Subject of a Formula
Forming Equations from Geometric Contexts
Algebraic Word Problems
Discriminant Quick Guide
Critical Rule: Flipping the Inequality Sign
Algebra Study Plan
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