Year 8 Introduction to Algebra Topic Test — Answers
Answer sheet with worked solutions for the Year 8 algebra topic test.
Success TutoringWorksheetsAnswer sheetYear 8 · Mathematics · AlgebraYear 8 Introduction to Algebra Topic Test — Answers
Part A: Simplifying Expressions (Like Terms)
1.Simplify: 5x + 9x + 9[1 mark]
Answer: 14x + 9
- 5x + 9x = 14x
2.Simplify: 3x + 7x + 6[1 mark]
Answer: 10x + 6
- 3x + 7x = 10x
3.Simplify: −5x − 2x + 7[1 mark]
Answer: −7x + 7
- −5x − 2x = −7x
4.Simplify: 6x + 4x + 7[1 mark]
Answer: 10x + 7
- 6x + 4x = 10x
5.Simplify: 2x − 4x + 1[1 mark]
Answer: −2x + 1
- 2x − 4x = −2x
6.Simplify: −6x + 4x + 8[1 mark]
Answer: −2x + 8
- −6x + 4x = −2x
7.Simplify: −5x + 5x + 8[1 mark]
Answer: 8
- −5x + 5x = 0
8.Simplify: 4x + 4x + 9[1 mark]
Answer: 8x + 9
- 4x + 4x = 8x
Part B: Substitution
9.Find the value of 5x − 9 when x = 2[2 marks]
Answer: 1
- 5 × 2 − 9
- = 10 − 9 = 1
10.Find the value of 3x − 1 when x = 2[2 marks]
Answer: 5
- 3 × 2 − 1
- = 6 − 1 = 5
11.Find the value of −5x − 4 when x = 9[2 marks]
Answer: −49
- −5 × 9 − 4
- = −45 − 4 = −49
12.Find the value of −4x − 8 when x = 3[2 marks]
Answer: −20
- −4 × 3 − 8
- = −12 − 8 = −20
13.Find the value of −x + 3 when x = 3[2 marks]
Answer: 0
- −1 × 3 + 3
- = −3 + 3 = 0
14.Find the value of 2x + 5 when x = 6[2 marks]
Answer: 17
- 2 × 6 + 5
- = 12 + 5 = 17
Part C: Solving Linear Equations
15.3x = 9[2 marks]
Answer: x = 3
- Divide both sides by 3
- x = 9 ÷ 3 = 3
16.x + 7 = 9[2 marks]
Answer: x = 2
- Subtract 7 from both sides
- x = 9 − 7 = 2
17.x + 10 = 13[2 marks]
Answer: x = 3
- Subtract 10 from both sides
- x = 13 − 10 = 3
18.x + 9 = 19[2 marks]
Answer: x = 10
- Subtract 9 from both sides
- x = 19 − 9 = 10
19.x + 3 = 7[2 marks]
Answer: x = 4
- Subtract 3 from both sides
- x = 7 − 3 = 4
20.x − 8 = 0[2 marks]
Answer: x = 8
- Add 8 to both sides
- x = 0 + 8 = 8
21.x − 1 = 5[2 marks]
Answer: x = 6
- Add 1 to both sides
- x = 5 + 1 = 6
22.2x = 24[2 marks]
Answer: x = 12
- Divide both sides by 2
- x = 24 ÷ 2 = 12
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.