9th Grade Systems of Equations Worksheet — Level 3 — Practice Set 4 — Answers
Answer sheet with worked solutions for the 9th Grade systems of equations worksheet.
Success TutoringWorksheetsAnswer sheet9th Grade · Mathematics · Simultaneous Equations9th Grade Systems of Equations Worksheet — Level 3 — Practice Set 4 — Answers
Solve each pair of equations. Check your solution satisfies both equations.
1.Solve the system: 3x + y = −16 and 3x + 4y = −10
Answer: x = −6, y = 2
- Subtract equation 2 from equation 1: −3y = −6
- y = 2
- Substitute into equation 1: 3x + 2 = −16, so x = −6
2.Solve the system: 3x + y = 16 and 4x + 2y = 20
Answer: x = 6, y = −2
- Multiply equation 1 by 4 and equation 2 by 3 to match the x coefficients
- 12x + 4y = 64 and 12x + 6y = 60
- Subtract: −2y = 4, so y = −2
- Substitute back: x = 6
3.Solve the system: 2x + 2y = 16 and 5x − 5y = −30
Answer: x = 1, y = 7
- Multiply equation 1 by 5 and equation 2 by 2 to match the x coefficients
- 10x + 10y = 80 and 10x − 10y = −60
- Subtract: 20y = 140, so y = 7
- Substitute back: x = 1
4.Solve the system: 3x + 4y = −16 and 3x − 3y = −9
Answer: x = −4, y = −1
- Subtract equation 2 from equation 1: 7y = −7
- y = −1
- Substitute into equation 1: 3x − 4 = −16, so x = −4
5.Solve the system: 4x − 3y = 20 and 2x + 5y = 36
Answer: x = 8, y = 4
- Multiply equation 1 by 2 and equation 2 by 4 to match the x coefficients
- 8x − 6y = 40 and 8x + 20y = 144
- Subtract: −26y = −104, so y = 4
- Substitute back: x = 8
6.Solve the system: 2x + 4y = 32 and 3x − y = −1
Answer: x = 2, y = 7
- Multiply equation 1 by 3 and equation 2 by 2 to match the x coefficients
- 6x + 12y = 96 and 6x − 2y = −2
- Subtract: 14y = 98, so y = 7
- Substitute back: x = 2
7.Solve the system: 2x − y = 0 and 5x + y = 7
Answer: x = 1, y = 2
- Multiply equation 1 by 5 and equation 2 by 2 to match the x coefficients
- 10x − 5y = 0 and 10x + 2y = 14
- Subtract: −7y = −14, so y = 2
- Substitute back: x = 1
8.Solve the system: 4x + 4y = 12 and 5x − 4y = −57
Answer: x = −5, y = 8
- Multiply equation 1 by 5 and equation 2 by 4 to match the x coefficients
- 20x + 20y = 60 and 20x − 16y = −228
- Subtract: 36y = 288, so y = 8
- Substitute back: x = −5
Marking tips
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