Edexcel GCSE Foundation Maths: Factoring
What are Factors?
Factors are numbers that divide evenly into another number. For example, the factors of 12 are:
What is Factoring?
Factoring is the process of breaking down a number or an algebraic expression into its factors.
Factoring Expressions:
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Finding the Highest Common Factor (HCF):
- Step 1: Identify the common factors of all the terms in the expression.
- Step 2: Find the highest common factor (HCF).
- Step 3: Divide each term in the expression by the HCF.
- Step 4: Write the HCF outside brackets and the results of the division inside the brackets.
Example: Factorise 6x + 9
- Step 1: Common factors are 3 and 1.
- Step 2: HCF is 3.
- Step 3: 6x/3 = 2x and 9/3 = 3
- Step 4: 6x + 9 = 3(2x + 3)
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Factoring Quadratics:
- Step 1: Identify the coefficients of the quadratic expression (a, b, and c in ax² + bx + c).
- Step 2: Find two numbers that multiply to give 'ac' and add up to 'b'.
- Step 3: Rewrite the middle term (bx) using the two numbers found in step 2.
- Step 4: Factorise the expression by grouping the terms.
Example: Factorise x² + 5x + 6
- Step 1: a = 1, b = 5, c = 6
- Step 2: Two numbers that multiply to 6 and add to 5 are 2 and 3.
- Step 3: x² + 5x + 6 = x² + 2x + 3x + 6
- Step 4: x² + 2x + 3x + 6 = x(x + 2) + 3(x + 2) = (x + 2)(x + 3)
Why Factoring is Important:
Factoring is an important skill in algebra as it allows us to:
- Simplify expressions: Factoring can make expressions easier to work with and solve.
- Solve equations: Factoring can be used to solve quadratic equations.
- Analyze functions: Factoring can help us understand the behavior of polynomial functions.
Practice Exercises:
- Factorise the following expressions:
- 4x + 8
- 5y² - 10y
- 2a² + 6a + 4
- Solve the following equations by factoring:
- x² - 4x = 0
- y² + 7y + 10 = 0
Remember: Practice makes perfect! The more you practice factoring, the easier it will become.