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Number and Algebra
Quick questions on Algebraic manipulation and factorisation explained: N(A)-Level Mathematics Number and Algebra
7short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.
What are like terms?Show answer
Like terms have exactly the same letters raised to the same powers, for example and , or and . You can only add or subtract like terms:
What are expanding single brackets?Show answer
Multiply the term outside the bracket by each term inside:
What are expanding double brackets?Show answer
Each term in the first bracket multiplies each term in the second. A reliable order is First, Outer, Inner, Last (FOIL):
What is factorising with a common factor?Show answer
Factorising is the reverse of expanding. Look for the highest common factor of all the terms and write it outside a bracket:
What is substituting values into an expression?Show answer
Algebra becomes a number once you replace each letter with a value. To evaluate when and , substitute and work out: . Use brackets when you substitute a negative number, for example with becomes . Simplifying an expression before substituting usually makes the arithmetic shorter and safer.
What is sign errors expanding a negative bracket?Show answer
is , not .
What is only expanding part of a double bracket?Show answer
Every term in the first bracket must multiply every term in the second; FOIL has four products.
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