Expanding two brackets with FOIL
Produce four products then collect like terms reliably.
Key formulas
What this lesson covers
This lesson builds Secondary 2–3 skill in FOIL expand. Read the key formulas, study the worked example, then attempt the written practice and the four-question MCQ review.
Method
Write every step. Name the rule you use (FOIL expand) before substituting numbers. Keep units and signs visible until the final sentence.
Common mistakes
Students often rush the sign, use the wrong percentage base, or cancel terms instead of factors. Pause after each line and ask whether the step is reversible.
Exam habit
Underline the question verb (simplify, solve, factorise, find). Box the final answer and, where sensible, substitute back for a quick check.
Worked example
Worked example — FOIL expand
Problem. Apply the method for FOIL expand with the numbers 9 and 6.
Solution. Identify the rule for FOIL expand. Substitute 9 and 6 carefully with signs in brackets if needed. Complete each operation on a new line. State the final answer clearly and check by reversing one step.
Review quiz
1 / 4Warm-up on FOIL expand: what is 5+5?
Practice questions
- Practice 1 on FOIL expand: compute with the value 33.
- Practice 2 on FOIL expand: change the numbers and repeat the same method.
- Practice 3 on FOIL expand: write one sentence explaining the key rule.
- Practice 4 on FOIL expand: invent a similar exam-style question and solve it.
Study notes
What is the main idea of FOIL expand?
Apply the stated formula or rule with clear steps, then check by reversing or substituting.
How should I revise this topic?
Cover the worked example, redo the practice without notes, then complete the MCQ set and log any wrong options.