Comprehensive practice sheet featuring 12 problems designed to help students master solving systems of linear equations using the elimination method.
Kuta Software Infinite Algebra 1 worksheet for solving systems of equations by elimination with 12 practice problems.
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Step-by-step solution for: Systems of Equations Elimination worksheet
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Show Answer Key & Explanations
Step-by-step solution for: Systems of Equations Elimination worksheet
Let’s solve each system of equations by elimination. We’ll go one at a time, carefully adding or subtracting the equations to eliminate one variable, then solving for the other.
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Problem 1:
-4x - 2y = -12
4x + 8y = -24
Add the two equations together (the x terms will cancel):
(-4x + 4x) + (-2y + 8y) = -12 + (-24)
0x + 6y = -36
→ 6y = -36
→ y = -6
Now plug y = -6 into one of the original equations. Let’s use the first:
-4x - 2(-6) = -12
-4x + 12 = -12
-4x = -24
x = 6
✔ Solution: (6, -6)
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Problem 2:
4x + 8y = 20
-4x + 2y = -30
Add them (x cancels again):
(4x - 4x) + (8y + 2y) = 20 + (-30)
0x + 10y = -10
→ 10y = -10
→ y = -1
Plug into first equation:
4x + 8(-1) = 20
4x - 8 = 20
4x = 28
x = 7
✔ Solution: (7, -1)
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Problem 3:
x - y = 11
2x + y = 19
Add them (y cancels):
(x + 2x) + (-y + y) = 11 + 19
3x + 0y = 30
→ 3x = 30
→ x = 10
Plug into first equation:
10 - y = 11
-y = 1
y = -1
✔ Solution: (10, -1)
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Problem 4:
-6x + 5y = 1
6x + 4y = -10
Add them (x cancels):
(-6x + 6x) + (5y + 4y) = 1 + (-10)
0x + 9y = -9
→ 9y = -9
→ y = -1
Plug into second equation:
6x + 4(-1) = -10
6x - 4 = -10
6x = -6
x = -1
✔ Solution: (-1, -1)
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Problem 5:
-2x - 9y = -25
-4x - 9y = -23
Subtract the first equation from the second to eliminate y:
(-4x - 9y) - (-2x - 9y) = -23 - (-25)
-4x - 9y + 2x + 9y = -23 + 25
-2x = 2
→ x = -1
Plug into first equation:
-2(-1) - 9y = -25
2 - 9y = -25
-9y = -27
y = 3
✔ Solution: (-1, 3)
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Problem 6:
8x + y = -16
-3x + y = -5
Subtract the second equation from the first to eliminate y:
(8x + y) - (-3x + y) = -16 - (-5)
8x + y + 3x - y = -16 + 5
11x = -11
→ x = -1
Plug into first equation:
8(-1) + y = -16
-8 + y = -16
y = -8
✔ Solution: (-1, -8)
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Problem 7:
-6x + 6y = 6
-6x + 3y = -12
Subtract the second equation from the first:
(-6x + 6y) - (-6x + 3y) = 6 - (-12)
-6x + 6y + 6x - 3y = 6 + 12
3y = 18
→ y = 6
Plug into first equation:
-6x + 6(6) = 6
-6x + 36 = 6
-6x = -30
x = 5
✔ Solution: (5, 6)
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Problem 8:
7x + 2y = 24
8x + 2y = 30
Subtract first from second:
(8x + 2y) - (7x + 2y) = 30 - 24
8x + 2y - 7x - 2y = 6
x = 6
Plug into first equation:
7(6) + 2y = 24
42 + 2y = 24
2y = -18
y = -9
✔ Solution: (6, -9)
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Problem 9:
5x + y = 9
10x - 7y = -18
Multiply first equation by 7 so we can eliminate y:
7*(5x + y) = 7*9 → 35x + 7y = 63
Now add to second equation:
35x + 7y = 63
10x - 7y = -18
------------------
45x + 0y = 45
→ 45x = 45
→ x = 1
Plug into first equation:
5(1) + y = 9
5 + y = 9
y = 4
✔ Solution: (1, 4)
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Problem 10:
-4x + 9y = 9
x - 3y = -6
Multiply second equation by 3 to match coefficients of y:
3*(x - 3y) = 3*(-6) → 3x - 9y = -18
Now add to first equation:
-4x + 9y = 9
3x - 9y = -18
------------------
-x + 0y = -9
→ -x = -9
→ x = 9
Plug into second equation:
9 - 3y = -6
-3y = -15
y = 5
✔ Solution: (9, 5)
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Problem 11:
-3x + 7y = -16
-9x + 5y = 16
Multiply first equation by 3 to match x-coefficients:
3*(-3x + 7y) = 3*(-16) → -9x + 21y = -48
Now subtract second equation from this:
(-9x + 21y) - (-9x + 5y) = -48 - 16
-9x + 21y + 9x - 5y = -64
16y = -64
→ y = -4
Plug into first equation:
-3x + 7(-4) = -16
-3x - 28 = -16
-3x = 12
x = -4
✔ Solution: (-4, -4)
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Problem 12:
-7x + y = -19
-2x + 3y = -19
Multiply first equation by 3 to match y-coefficients:
3*(-7x + y) = 3*(-19) → -21x + 3y = -57
Now subtract second equation from this:
(-21x + 3y) - (-2x + 3y) = -57 - (-19)
-21x + 3y + 2x - 3y = -57 + 19
-19x = -38
→ x = 2
Plug into first equation:
-7(2) + y = -19
-14 + y = -19
y = -5
✔ Solution: (2, -5)
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Final Answer:
1) (6, -6)
2) (7, -1)
3) (10, -1)
4) (-1, -1)
5) (-1, 3)
6) (-1, -8)
7) (5, 6)
8) (6, -9)
9) (1, 4)
10) (9, 5)
11) (-4, -4)
12) (2, -5)
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Problem 1:
-4x - 2y = -12
4x + 8y = -24
Add the two equations together (the x terms will cancel):
(-4x + 4x) + (-2y + 8y) = -12 + (-24)
0x + 6y = -36
→ 6y = -36
→ y = -6
Now plug y = -6 into one of the original equations. Let’s use the first:
-4x - 2(-6) = -12
-4x + 12 = -12
-4x = -24
x = 6
✔ Solution: (6, -6)
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Problem 2:
4x + 8y = 20
-4x + 2y = -30
Add them (x cancels again):
(4x - 4x) + (8y + 2y) = 20 + (-30)
0x + 10y = -10
→ 10y = -10
→ y = -1
Plug into first equation:
4x + 8(-1) = 20
4x - 8 = 20
4x = 28
x = 7
✔ Solution: (7, -1)
---
Problem 3:
x - y = 11
2x + y = 19
Add them (y cancels):
(x + 2x) + (-y + y) = 11 + 19
3x + 0y = 30
→ 3x = 30
→ x = 10
Plug into first equation:
10 - y = 11
-y = 1
y = -1
✔ Solution: (10, -1)
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Problem 4:
-6x + 5y = 1
6x + 4y = -10
Add them (x cancels):
(-6x + 6x) + (5y + 4y) = 1 + (-10)
0x + 9y = -9
→ 9y = -9
→ y = -1
Plug into second equation:
6x + 4(-1) = -10
6x - 4 = -10
6x = -6
x = -1
✔ Solution: (-1, -1)
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Problem 5:
-2x - 9y = -25
-4x - 9y = -23
Subtract the first equation from the second to eliminate y:
(-4x - 9y) - (-2x - 9y) = -23 - (-25)
-4x - 9y + 2x + 9y = -23 + 25
-2x = 2
→ x = -1
Plug into first equation:
-2(-1) - 9y = -25
2 - 9y = -25
-9y = -27
y = 3
✔ Solution: (-1, 3)
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Problem 6:
8x + y = -16
-3x + y = -5
Subtract the second equation from the first to eliminate y:
(8x + y) - (-3x + y) = -16 - (-5)
8x + y + 3x - y = -16 + 5
11x = -11
→ x = -1
Plug into first equation:
8(-1) + y = -16
-8 + y = -16
y = -8
✔ Solution: (-1, -8)
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Problem 7:
-6x + 6y = 6
-6x + 3y = -12
Subtract the second equation from the first:
(-6x + 6y) - (-6x + 3y) = 6 - (-12)
-6x + 6y + 6x - 3y = 6 + 12
3y = 18
→ y = 6
Plug into first equation:
-6x + 6(6) = 6
-6x + 36 = 6
-6x = -30
x = 5
✔ Solution: (5, 6)
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Problem 8:
7x + 2y = 24
8x + 2y = 30
Subtract first from second:
(8x + 2y) - (7x + 2y) = 30 - 24
8x + 2y - 7x - 2y = 6
x = 6
Plug into first equation:
7(6) + 2y = 24
42 + 2y = 24
2y = -18
y = -9
✔ Solution: (6, -9)
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Problem 9:
5x + y = 9
10x - 7y = -18
Multiply first equation by 7 so we can eliminate y:
7*(5x + y) = 7*9 → 35x + 7y = 63
Now add to second equation:
35x + 7y = 63
10x - 7y = -18
------------------
45x + 0y = 45
→ 45x = 45
→ x = 1
Plug into first equation:
5(1) + y = 9
5 + y = 9
y = 4
✔ Solution: (1, 4)
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Problem 10:
-4x + 9y = 9
x - 3y = -6
Multiply second equation by 3 to match coefficients of y:
3*(x - 3y) = 3*(-6) → 3x - 9y = -18
Now add to first equation:
-4x + 9y = 9
3x - 9y = -18
------------------
-x + 0y = -9
→ -x = -9
→ x = 9
Plug into second equation:
9 - 3y = -6
-3y = -15
y = 5
✔ Solution: (9, 5)
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Problem 11:
-3x + 7y = -16
-9x + 5y = 16
Multiply first equation by 3 to match x-coefficients:
3*(-3x + 7y) = 3*(-16) → -9x + 21y = -48
Now subtract second equation from this:
(-9x + 21y) - (-9x + 5y) = -48 - 16
-9x + 21y + 9x - 5y = -64
16y = -64
→ y = -4
Plug into first equation:
-3x + 7(-4) = -16
-3x - 28 = -16
-3x = 12
x = -4
✔ Solution: (-4, -4)
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Problem 12:
-7x + y = -19
-2x + 3y = -19
Multiply first equation by 3 to match y-coefficients:
3*(-7x + y) = 3*(-19) → -21x + 3y = -57
Now subtract second equation from this:
(-21x + 3y) - (-2x + 3y) = -57 - (-19)
-21x + 3y + 2x - 3y = -57 + 19
-19x = -38
→ x = 2
Plug into first equation:
-7(2) + y = -19
-14 + y = -19
y = -5
✔ Solution: (2, -5)
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Final Answer:
1) (6, -6)
2) (7, -1)
3) (10, -1)
4) (-1, -1)
5) (-1, 3)
6) (-1, -8)
7) (5, 6)
8) (6, -9)
9) (1, 4)
10) (9, 5)
11) (-4, -4)
12) (2, -5)
Parent Tip: Review the logic above to help your child master the concept of systems of equations elimination worksheet.