Year 9 Gradient and Linear Equations Worksheet — Level 3 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 9 linear relationships & graphs worksheet.
Year 9 Gradient and Linear Equations Worksheet — Level 3 — Practice Set 4 — Answers
Show your working. Gradient = rise ÷ run; the equation of a line can be written as y = (gradient)x + (y-intercept).
Answer: gradient −5; y-intercept 9
In y = (gradient)x + (y-intercept), the number multiplying x is the gradient and the constant is where the line crosses the y-axis.
Answer: y = 2x − 5
- y = 2x + (y-intercept)
- −5 = 2 × 0 + (y-intercept)
- y-intercept = −5 − 0 = −5
- y = 2x − 5
Answer: y = −2x + 8
- y = −2x + (y-intercept)
- 16 = −2 × (−4) + (y-intercept)
- y-intercept = 16 − 8 = 8
- y = −2x + 8
Answer: gradient 4; y-intercept −4
In y = (gradient)x + (y-intercept), the number multiplying x is the gradient and the constant is where the line crosses the y-axis.
Answer: gradient −4; y-intercept 7
In y = (gradient)x + (y-intercept), the number multiplying x is the gradient and the constant is where the line crosses the y-axis.
Answer: y = 4x − 3
- y = 4x + (y-intercept)
- −7 = 4 × (−1) + (y-intercept)
- y-intercept = −7 − (−4) = −3
- y = 4x − 3
Answer: y = −5x
- y = −5x + (y-intercept)
- 15 = −5 × (−3) + (y-intercept)
- y-intercept = 15 − 15 = 0
- y = −5x
Answer: y = 5x + 8
- y = 5x + (y-intercept)
- 28 = 5 × 4 + (y-intercept)
- y-intercept = 28 − 20 = 8
- y = 5x + 8
Answer: y = 3x + 9
- y = 3x + (y-intercept)
- 0 = 3 × (−3) + (y-intercept)
- y-intercept = 0 − (−9) = 9
- y = 3x + 9
Answer: y = −3x + 2
- y = −3x + (y-intercept)
- 8 = −3 × (−2) + (y-intercept)
- y-intercept = 8 − 6 = 2
- y = −3x + 2
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.