Year 9 Gradient and Linear Equations Worksheet — Level 3 — Practice Set 2 — 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 2 — Answers
Show your working. Gradient = rise ÷ run; the equation of a line can be written as y = (gradient)x + (y-intercept).
- AYes
- BNo
Answer: Yes
Substitute x = −1: y = 1 × (−1) + 1 = 0, which matches.
Answer: y = 2x + 2
- y = 2x + (y-intercept)
- −4 = 2 × (−3) + (y-intercept)
- y-intercept = −4 − (−6) = 2
- y = 2x + 2
Answer: y = −2x − 3
- y = −2x + (y-intercept)
- −7 = −2 × 2 + (y-intercept)
- y-intercept = −7 − (−4) = −3
- y = −2x − 3
- AYes
- BNo
Answer: No
Substitute x = −2: y = 3 × (−2) + 3 = −3, not −4.
Answer: y = x + 5
- y = 1x + (y-intercept)
- 8 = 1 × 3 + (y-intercept)
- y-intercept = 8 − 3 = 5
- y = x + 5
Answer: y = 5x + 1
- y = 5x + (y-intercept)
- −14 = 5 × (−3) + (y-intercept)
- y-intercept = −14 − (−15) = 1
- y = 5x + 1
- AYes
- BNo
Answer: Yes
Substitute x = 4: y = −2 × 4 − 7 = −15, which matches.
Answer: gradient −2; y-intercept 5
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 1
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)
- 13 = −4 × (−4) + (y-intercept)
- y-intercept = 13 − 16 = −3
- y = −4x − 3
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.