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Year 9 Factorising Expressions (Common Factors) Worksheet — Level 1 — Practice Set 4 — Answers

Answer sheet with worked solutions for the Year 9 algebraic expressions worksheet.

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Success TutoringWorksheetsAnswer sheetYear 9 · Mathematics · Algebraic Expressions

Year 9 Factorising Expressions (Common Factors) Worksheet — Level 1 — Practice Set 4 — Answers

Find the highest common factor of the terms and write it outside the brackets.

1.Factorise fully: 6x − 18

Answer: 6(x − 3)

  1. Highest common factor: 6
  2. 6x − 18 = 6(x − 3)
  3. Check by expanding the brackets.
2.Factorise fully: 10x − 2

Answer: 2(5x − 1)

  1. Highest common factor: 2
  2. 10x − 2 = 2(5x − 1)
  3. Check by expanding the brackets.
3.Factorise fully: 18x + 81

Answer: 9(2x + 9)

  1. Highest common factor: 9
  2. 18x + 81 = 9(2x + 9)
  3. Check by expanding the brackets.
4.Factorise fully: 20x − 15

Answer: 5(4x − 3)

  1. Highest common factor: 5
  2. 20x − 15 = 5(4x − 3)
  3. Check by expanding the brackets.
5.Factorise fully: 45x + 18

Answer: 9(5x + 2)

  1. Highest common factor: 9
  2. 45x + 18 = 9(5x + 2)
  3. Check by expanding the brackets.
6.Factorise fully: 9x − 3

Answer: 3(3x − 1)

  1. Highest common factor: 3
  2. 9x − 3 = 3(3x − 1)
  3. Check by expanding the brackets.
7.Factorise fully: 18x − 12

Answer: 6(3x − 2)

  1. Highest common factor: 6
  2. 18x − 12 = 6(3x − 2)
  3. Check by expanding the brackets.
8.Factorise fully: 5x + 25

Answer: 5(x + 5)

  1. Highest common factor: 5
  2. 5x + 25 = 5(x + 5)
  3. Check by expanding the brackets.
9.Factorise fully: 24x + 28

Answer: 4(6x + 7)

  1. Highest common factor: 4
  2. 24x + 28 = 4(6x + 7)
  3. Check by expanding the brackets.
10.Factorise fully: 3x + 3

Answer: 3(x + 1)

  1. Highest common factor: 3
  2. 3x + 3 = 3(x + 1)
  3. Check by expanding the brackets.
11.Factorise fully: 35x + 7

Answer: 7(5x + 1)

  1. Highest common factor: 7
  2. 35x + 7 = 7(5x + 1)
  3. Check by expanding the brackets.
12.Factorise fully: 45x − 81

Answer: 9(5x − 9)

  1. Highest common factor: 9
  2. 45x − 81 = 9(5x − 9)
  3. Check by expanding the brackets.
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