Year 10 Simultaneous Equations Worksheet — Level 3 — Answers
Answer sheet with worked solutions for the Year 10 simultaneous equations worksheet.
Year 10 Simultaneous Equations Worksheet — Level 3 — Answers
Solve each pair of equations. Check your solution satisfies both equations.
1.Solve simultaneously: 3x + y = −1 and 5x − 2y = −9
Answer: x = −1, y = 2
- Multiply equation 1 by 5 and equation 2 by 3 to match the x coefficients
- 15x + 5y = −5 and 15x − 6y = −27
- Subtract: 11y = 22, so y = 2
- Substitute back: x = −1
2.Solve simultaneously: 2x + 2y = −6 and 5x − 3y = −31
Answer: x = −5, y = 2
- Multiply equation 1 by 5 and equation 2 by 2 to match the x coefficients
- 10x + 10y = −30 and 10x − 6y = −62
- Subtract: 16y = 32, so y = 2
- Substitute back: x = −5
3.Solve simultaneously: 4x − 3y = −2 and 5x − 4y = −2
Answer: x = −2, y = −2
- Multiply equation 1 by 5 and equation 2 by 4 to match the x coefficients
- 20x − 15y = −10 and 20x − 16y = −8
- Subtract: y = −2, so y = −2
- Substitute back: x = −2
4.Solve simultaneously: 4x + 4y = −36 and 4x − 3y = −1
Answer: x = −4, y = −5
- Subtract equation 2 from equation 1: 7y = −35
- y = −5
- Substitute into equation 1: 4x − 20 = −36, so x = −4
5.Solve simultaneously: 4x + 3y = −6 and 2x − 4y = −36
Answer: x = −6, y = 6
- Multiply equation 1 by 2 and equation 2 by 4 to match the x coefficients
- 8x + 6y = −12 and 8x − 16y = −144
- Subtract: 22y = 132, so y = 6
- Substitute back: x = −6
6.Solve simultaneously: 2x − 4y = −22 and 4x − y = 5
Answer: x = 3, y = 7
- Multiply equation 1 by 4 and equation 2 by 2 to match the x coefficients
- 8x − 16y = −88 and 8x − 2y = 10
- Subtract: −14y = −98, so y = 7
- Substitute back: x = 3
7.Solve simultaneously: 3x + y = 10 and 5x − y = 6
Answer: x = 2, y = 4
- Multiply equation 1 by 5 and equation 2 by 3 to match the x coefficients
- 15x + 5y = 50 and 15x − 3y = 18
- Subtract: 8y = 32, so y = 4
- Substitute back: x = 2
8.Solve simultaneously: 2x + 2y = 6 and 3x − 5y = −31
Answer: x = −2, y = 5
- Multiply equation 1 by 3 and equation 2 by 2 to match the x coefficients
- 6x + 6y = 18 and 6x − 10y = −62
- Subtract: 16y = 80, so y = 5
- Substitute back: x = −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.