Algebra and equations

Explain algebraic equivalence, simplify rational expressions and solve linear, simultaneous and quadratic conditions while retaining restrictions.

  • 22 lessons

Notation, evaluation and algebraic models

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SEAB syllabus · 2027 · MOE syllabus

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About this topic

Before you begin

Explain algebraic equivalence, simplify rational expressions and solve linear, simultaneous and quadratic conditions while retaining restrictions.

Learning goals
  • Evaluate an algebraic expression by substitution
  • Represent a situation with algebraic expressions
  • Interpret algebraic notation and represented operations
  • Simplify linear expressions by combining like terms
  • Expand and factorise algebraic expressions
  • Express and use the general term of a sequence
  • Solve linear equations and check the solution
  • Formulate, use and interpret a mathematical model
  • Change the subject of a formula
  • Multiply and divide algebraic fractions with domain restrictions
  • Calculate and simplify algebraic fractions with restrictions
  • Add and subtract algebraic fractions with domain restrictions
  • Solve a first-degree equation by a specified expansion or denominator-clearing step, preserving original exclusions
  • Solve a system of linear equations completely, including systems with no or infinitely many solutions
  • Solve simultaneous equations by justified methods
  • Interpret and draw graphs of functions
  • Solve quadratic equations by suitable methods
  • Apply the quadratic formula with signed coefficients, both branches and the complete real solution set
  • Solve linear inequalities and show the solution set on a number line
  • Solve inequalities and represent their solution sets
Syllabus statements covered
  • Using letters to represent numbers
  • Interpreting notations: ab as a × b; a/b as a ÷ b or a × (1/b); a² as a × a, a³ as a × a × a, a²b as a × a × b, …; 3y as y + y + y or 3 × y; 3(x + y) as 3 × (x + y); (3 + y)/5 as (3 + y) ÷ 5 or (1/5) × (3 + y)
  • Evaluation of algebraic expressions and formulae
  • Translation of simple real-world situations into algebraic expressions
  • Recognising and representing patterns/relationships by finding an algebraic expression for the nth term
  • Addition and subtraction of linear expressions
  • Simplification of linear expressions such as −2(3x − 5) + 4x and 2x/3 − 3(x − 5)/2
  • Use brackets and extract common factors
  • Factorisation of linear expressions ax + bx + kay + kby
  • Expansion of the product of algebraic expressions
  • Changing the subject of a formula
  • Finding the value of an unknown quantity in a given formula
  • Use of (a + b)² = a² + 2ab + b², (a − b)² = a² − 2ab + b², a² − b² = (a + b)(a − b)
  • Factorisation of quadratic expressions ax² + bx + c
  • Multiplication and division of simple algebraic fractions such as (3a/(4b²))(5ab/3); (3a/4) ÷ (9a²/10)
  • Addition and subtraction of algebraic fractions with linear or quadratic denominator such as 1/(x − 2) + 2/(x − 3); 1/(x² − 9) + 2/(x − 3); 1/(x − 3) + 2/(x − 3)²
  • Solving linear equations in one variable
  • Solving simple fractional equations that reduce to linear equations, such as x/3 + (x − 2)/4 = 3 and 3/(x − 2) = 6
  • Solving simultaneous linear equations in two variables by substitution and elimination or graphically
  • Solving quadratic equations in one variable by factorisation, formula, completing the square for y = x² + px + q, or graphically
  • Solving fractional equations that reduce to quadratics, such as 6/(x + 4) = x + 3 and 1/(x − 2) + 2/(x − 3) = 5
  • Formulating equations to solve problems
  • Solving linear inequalities in one variable and representing the solution on the number line
  • Using letters to represent numbers
  • Interpreting notations: ab as a × b; a/b as a ÷ b or a × (1/b); a² as a × a, a³ as a × a × a, a²b as a × a × b, …; 3y as y + y + y or 3 × y; 3(x + y) as 3 × (x + y); (3 + y)/5 as (3 + y) ÷ 5 or (1/5) × (3 + y)
  • Evaluation of algebraic expressions and formulae
  • Translation of simple real-world situations into algebraic expressions
  • Recognising and representing patterns/relationships by finding an algebraic expression for the nth term
  • Addition and subtraction of linear expressions
  • Simplification of linear expressions such as −2(3x − 5) + 4x; 2x/3 − 3(x − 5)/2
  • Use brackets and extract common factors
  • Concept of equation
  • Solving linear equations in one variable
  • Solving simple fractional equations that can be reduced to linear equations such as x/3 + (x − 2)/4 = 3; 3/(x − 2) = 6
  • Formulating a linear equation in one variable to solve problems
  • Expansion of the product of algebraic expressions
  • Changing the subject of a formula
  • Finding the value of an unknown quantity in a given formula
  • Use of:
  • (a + b)² = a^2 + 2ab + b^2
  • (a − b)² = a^2 − 2ab + b^2
  • a^2 − b^2 = (a + b)(a − b)
  • Factorisation of linear expressions of the form ax + bx + kay + kby
  • Factorisation of quadratic expressions ax^2 + bx + c
  • Multiplication and division of simple algebraic fractions such as (3a/(4b²))(5ab/3); (3a/4) ÷ (9a²/10)
  • Addition and subtraction of algebraic fractions with linear or quadratic denominator such as 1/(x − 2) + 2/(x − 3); 1/(x² − 9) + 2/(x − 3); 1/(x − 3) + 2/(x − 3)²
  • Concept of equation and inequality
  • Solving simple inequalities in the form ax + b ≤ c and ax + b < c and representing the solutions on the number line
  • Graphs of linear equations in two variables (ax + by = c)
  • Solving simultaneous linear equations in two variables by:
  • Substitution and elimination methods
  • Graphical method
  • Solving quadratic equations in one variable by factorisation
  • Formulating a pair of linear equations in two variables to solve problems
  • Solving quadratic equations in one variable by:
  • Use of formula
  • Completing the square for y = x^2 + px + q
  • Graphical method
  • Solving fractional equations that can be reduced to quadratic equations such as 6/(x + 4) = x + 3; 1/(x − 2) + 2/(x − 3) = 5
  • Solving linear inequalities in one variable (including simultaneous inequalities) and representing the solution on the number line
  • Formulating a quadratic equation in one variable to solve problems

Choose a lesson

Work through them in order.

  1. Not startedNotation, evaluation and algebraic modelsNextInterpret grouped algebraic notation and define a letter before substituting a value.
  2. Not startedExpressions and equivalenceDistinguish an expression from an equation and justify equivalent algebraic forms.
  3. Not startedRead a sequence ruleUse the given position in a stated rule without confusing the term value with its index.
  4. Not startedLinear expressions with integer coefficientsDistribute every sign through a bracket and combine only like terms.
  5. Not startedLinear expressions with fractional coefficientsUse common denominators to combine fractional linear coefficients without losing bracket signs.
  6. Not startedLinear equations with integer coefficientsApply the same reversible operation on both sides and check the answer in the original equation.
  7. Not startedEquations as balanced relationshipsPreserve equality through each solution step and test a candidate solution in the original equation.
  8. Not startedSequences and nth termsRelate a position to its term and distinguish a matching rule from evidence of a unique pattern.
  9. Not startedCommon factors and formula subjectsReverse distribution, change a formula's subject and find an unknown value from the given quantities.
  10. Not startedProducts and simple quadratic factorsDistribute two linear factors and reverse the product for monic quadratics.
  11. Not startedIdentities and general quadratic factorsDerive useful identities by distribution and verify every factorisation by expansion.
  12. Not startedFour-term common factorsGroup terms to expose a matching complete factor and verify it by expansion.
  13. Not startedAlgebraic fraction products and domainsCancel factors rather than terms and preserve exclusions when multiplying or dividing algebraic fractions.
  14. Not startedAlgebraic fraction sumsChoose a common denominator, retain excluded values and simplify only complete factors.
  15. Not startedFormulae and restrictionsRearrange formulae and simplify rational expressions while retaining nonzero-denominator restrictions.
  16. Not startedFractional linear equationsClear every denominator and check both the original domain and the solution.
  17. Not startedSimultaneous linear equationsConstruct two linear graphs, solve for their common pair and check graphical readings with algebra.
  18. Not startedZero products and quadratic equationsSet a factored quadratic equal to zero and retain every factor alternative.
  19. Not startedQuadratic formula and modelsIdentify coefficients, retain both possible roots and reject values only for a stated domain reason.
  20. Not startedCompleting the square and fractional quadraticsChoose an exact quadratic method and distinguish solving from rewriting a function.
  21. Not startedLinear inequalitiesReverse the order relation when multiplying or dividing by a negative number.
  22. Not startedSimultaneous linear inequalitiesIntersect conditions required together and retain the correct strict or inclusive endpoints.