Algebraic expressions are the building blocks of advanced maths, and... Show more
Mastering Algebraic Expressions: A-Level Pure Maths Chapter 1




Index Laws and Expanding Brackets
Index laws are your best mates when simplifying expressions with powers. Remember these four golden rules: , , , and .
When you're dividing algebraic fractions, split them up term by term. For example, becomes .
Expanding brackets means multiplying every term in one bracket by every term in another. With multiple brackets like , work systematically - expand two brackets first, then multiply by the third. Keep track of like terms and combine them at the end.
Top Tip: When expanding complex expressions, write out each step clearly to avoid silly mistakes - your future self will thank you!

Factorising and Index Rules
Factorising is basically expanding backwards - you're looking for common factors and patterns. Always start by taking out the highest common factor, like pulling out the 3 from $15x^2 + 42x - 93$.
For quadratics, you need two numbers that multiply to give the constant term and add to give the middle coefficient. In , you want numbers that multiply to 20 and add to 9 - that's 4 and 5, giving .
Negative and fractional indices follow the same rules but with twists: , , and . When solving equations like $27\sqrt[3]{x} = \frac{1}{x}$, rewrite everything using fractional indices first.
Remember: Factorising completely means you can't factor any further - always double-check your answer!

Surds and Rationalising Denominators
Surds are square roots that can't be simplified to whole numbers, and they follow specific manipulation rules: and .
To simplify surds like , look for perfect square factors. Since $75 = 25 \times 3\sqrt{75} = 5\sqrt{3}5\sqrt{3} - 2\sqrt{3} = 3\sqrt{3}$.
Rationalising denominators gets rid of surds from the bottom of fractions. For simple cases like , multiply top and bottom by . For expressions like , multiply by the conjugate - this creates a difference of squares that eliminates the surd.
Pro Strategy: Always multiply by the conjugate when you see addition or subtraction with surds in the denominator!
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Mastering Algebraic Expressions: A-Level Pure Maths Chapter 1
Algebraic expressions are the building blocks of advanced maths, and mastering them now will make A-level topics so much easier. This guide covers the essential skills you'll use constantly: index laws, expanding brackets, factorising, and working with surds.

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Index Laws and Expanding Brackets
Index laws are your best mates when simplifying expressions with powers. Remember these four golden rules: , , , and .
When you're dividing algebraic fractions, split them up term by term. For example, becomes .
Expanding brackets means multiplying every term in one bracket by every term in another. With multiple brackets like , work systematically - expand two brackets first, then multiply by the third. Keep track of like terms and combine them at the end.
Top Tip: When expanding complex expressions, write out each step clearly to avoid silly mistakes - your future self will thank you!

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- Access to all documents
- Improve your grades
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Factorising and Index Rules
Factorising is basically expanding backwards - you're looking for common factors and patterns. Always start by taking out the highest common factor, like pulling out the 3 from $15x^2 + 42x - 93$.
For quadratics, you need two numbers that multiply to give the constant term and add to give the middle coefficient. In , you want numbers that multiply to 20 and add to 9 - that's 4 and 5, giving .
Negative and fractional indices follow the same rules but with twists: , , and . When solving equations like $27\sqrt[3]{x} = \frac{1}{x}$, rewrite everything using fractional indices first.
Remember: Factorising completely means you can't factor any further - always double-check your answer!

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- Access to all documents
- Improve your grades
- Join milions of students
Surds and Rationalising Denominators
Surds are square roots that can't be simplified to whole numbers, and they follow specific manipulation rules: and .
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Rationalising denominators gets rid of surds from the bottom of fractions. For simple cases like , multiply top and bottom by . For expressions like , multiply by the conjugate - this creates a difference of squares that eliminates the surd.
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