Grade 10 Algebra worksheet focusing on solving simultaneous equations by elimination and substitution.
Grade 10 Mathematics worksheet on solving simultaneous equations using elimination and substitution methods.
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Step-by-step solution for: Grade 10 - Worksheets - Mathematics
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Show Answer Key & Explanations
Step-by-step solution for: Grade 10 - Worksheets - Mathematics
Let’s solve each pair of simultaneous equations step by step. We’ll use either elimination or substitution, whichever is easier for each problem.
---
3x + 3y = 21
2x - 2y = 6
We can simplify both equations first:
Divide first equation by 3:
→ x + y = 7 → (Equation A)
Divide second equation by 2:
→ x - y = 3 → (Equation B)
Now add Equation A and B:
(x + y) + (x - y) = 7 + 3
→ 2x = 10 → x = 5
Plug x = 5 into Equation A:
5 + y = 7 → y = 2
✔ Check:
3(5)+3(2)=15+6=21 ✔️
2(5)-2(2)=10-4=6 ✔️
---
5x + y = 8
2x + 3y = 13
Use substitution. From first equation:
y = 8 - 5x
Plug into second equation:
2x + 3(8 - 5x) = 13
2x + 24 - 15x = 13
-13x + 24 = 13
-13x = -11 → x = 11/13? Wait — that seems messy. Let me check again.
Wait — maybe I made a mistake. Let’s try elimination instead.
Multiply first equation by 3:
15x + 3y = 24
Second equation: 2x + 3y = 13
Subtract second from first:
(15x + 3y) - (2x + 3y) = 24 - 13
13x = 11 → x = 11/13? Still fraction. But let’s keep going.
Then y = 8 - 5*(11/13) = 8 - 55/13 = (104 - 55)/13 = 49/13
But this feels off — maybe the numbers are meant to be integers? Let me double-check original problem.
Original:
5x + y = 8
2x + 3y = 13
Try plugging in small integer values.
Try x=1: then y=3 → 2(1)+3(3)=2+9=11 ≠13
x=2: y=8-10=-2 → 2(2)+3(-2)=4-6=-2≠13
x=0: y=8 → 0+24=24≠13
x= -1: y=13 → 2(-1)+3(13)= -2+39=37≠13
Hmm. Maybe it’s correct as fractions? But let’s re-solve carefully.
From 5x + y = 8 → y = 8 - 5x
Plug into 2x + 3y = 13:
2x + 3(8 - 5x) = 13
2x + 24 - 15x = 13
-13x = 13 - 24 = -11
x = 11/13
y = 8 - 5*(11/13) = 104/13 - 55/13 = 49/13
So answer is x=11/13, y=49/13 — but that’s unusual for Grade 10. Maybe typo? Or perhaps we proceed.
Wait — let me check if I copied right. Original says:
“2. 5x + y = 8
2x + 3y = 13”
Yes. So unless there’s a typo, we go with fractions.
But let’s hold on — maybe I should do all problems and see pattern. Perhaps some have nice answers.
Actually, let’s assume it’s correct and move on. We’ll write fractional answers where needed.
But wait — let me try solving #2 again with elimination properly.
Eq1: 5x + y = 8
Eq2: 2x + 3y = 13
Multiply Eq1 by 3: 15x + 3y = 24
Keep Eq2: 2x + 3y = 13
Subtract Eq2 from modified Eq1:
(15x + 3y) - (2x + 3y) = 24 - 13
13x = 11 → x = 11/13
Same result. So yes, it’s correct.
But since this is Grade 10, maybe they expect decimal? Or perhaps I misread.
Wait — looking back at image description — user said “image contains task” — but I don’t have image, only text provided. The text says:
“2. 5x + y = 8
2x + 3y = 13”
So we must solve as given.
Proceeding.
x = 11/13, y = 49/13
But let’s write as mixed numbers or decimals? Better as fractions.
Alternatively, maybe the problem was meant to be 5x + y = 9? Then x=1, y=4 → 2+12=14 no. Or 5x+y=7? x=1,y=2 → 2+6=8 no.
I think we have to accept fractions here.
But let’s continue — maybe other problems are nicer.
---
4x - y = 17
2x - 2y = 10
Simplify second equation: divide by 2 → x - y = 5 → y = x - 5
Plug into first:
4x - (x - 5) = 17
4x - x + 5 = 17
3x = 12 → x = 4
Then y = 4 - 5 = -1
Check:
4(4) - (-1) = 16 +1 =17 ✔️
2(4) -2(-1)=8+2=10 ✔️
Good.
---
4x + 3y = 42
3x - y = 12
From second equation: y = 3x - 12
Plug into first:
4x + 3(3x - 12) = 42
4x + 9x - 36 = 42
13x = 78 → x = 6
Then y = 3(6) - 12 = 18 - 12 = 6
Check:
4(6)+3(6)=24+18=42 ✔️
3(6)-6=18-6=12 ✔️
Perfect.
---
3x - 2y = 5
4x + 5y = 45
Use elimination. Make coefficients of y same.
Multiply first by 5: 15x - 10y = 25
Multiply second by 2: 8x + 10y = 90
Add them:
15x -10y +8x +10y = 25+90
23x = 115 → x = 5
Plug into first: 3(5) -2y =5 → 15 -2y=5 → -2y= -10 → y=5
Check:
3(5)-2(5)=15-10=5 ✔️
4(5)+5(5)=20+25=45 ✔️
Great.
---
2x - 3y = 10
4x + 5y = 38
Eliminate x. Multiply first by 2: 4x - 6y = 20
Second: 4x + 5y = 38
Subtract first from second:
(4x +5y) - (4x -6y) = 38 - 20
4x +5y -4x +6y = 18
11y = 18 → y = 18/11
Then from first: 2x -3*(18/11) =10
2x - 54/11 = 10
2x = 10 + 54/11 = 110/11 + 54/11 = 164/11
x = 82/11
Check:
2*(82/11) -3*(18/11) = 164/11 - 54/11 = 110/11 =10 ✔️
4*(82/11) +5*(18/11) = 328/11 + 90/11 = 418/11 = 38 ✔️
So x=82/11, y=18/11
Again fractions — but mathematically correct.
---
x + 5y = 27
3x + 5y = 21
Subtract first from second:
(3x +5y) - (x +5y) = 21 - 27
2x = -6 → x = -3
Plug into first: -3 +5y=27 → 5y=30 → y=6
Check:
-3 +5*6= -3+30=27 ✔️
3*(-3)+5*6= -9+30=21 ✔️
Good.
---
2x - 2y = 8
5x - 3y = 22
Simplify first: divide by 2 → x - y = 4 → x = y + 4
Plug into second:
5(y+4) -3y =22
5y +20 -3y =22
2y =2 → y=1
Then x=1+4=5
Check:
2(5)-2(1)=10-2=8 ✔️
5(5)-3(1)=25-3=22 ✔️
Perfect.
---
2x + 5y = 26
x + 4y = 22
From second: x = 22 - 4y
Plug into first:
2(22 - 4y) +5y =26
44 -8y +5y =26
44 -3y =26
-3y = -18 → y=6
Then x=22 -4*6=22-24= -2
Check:
2(-2)+5(6)= -4+30=26 ✔️
-2 +4*6= -2+24=22 ✔️
Good.
---
Now, let’s list all answers clearly.
Note: Problems 2 and 6 gave fractional answers. Since the worksheet didn’t specify integer solutions, we present exact fractions.
Final Answers:
1. x = 5, y = 2
2. x = 11/13, y = 49/13
3. x = 4, y = -1
4. x = 6, y = 6
5. x = 5, y = 5
6. x = 82/11, y = 18/11
7. x = -3, y = 6
8. x = 5, y = 1
9. x = -2, y = 6
For problem 2 and 6, if decimals are preferred:
2. x ≈ 0.846, y ≈ 3.769
6. x ≈ 7.455, y ≈ 1.636
But since it's math, fractions are better.
However, let me double-check problem 2 — maybe I misread the original.
User wrote:
"2. 5x + y = 8
2x + 3y = 13"
What if it was 5x + y = 9? Then x=1, y=4 → 2+12=14 no.
Or 5x + y = 7? x=1,y=2 → 2+6=8 no.
Or 2x + 3y = 14? Then with x=1,y=3 → 2+9=11 no.
Perhaps it's correct as is.
Similarly for 6: 2x-3y=10, 4x+5y=38 — solution is indeed fractional.
So we'll go with fractions.
Final Answer:
1. x = 5, y = 2
2. x = \frac{11}{13}, y = \frac{49}{13}
3. x = 4, y = -1
4. x = 6, y = 6
5. x = 5, y = 5
6. x = \frac{82}{11}, y = \frac{18}{11}
7. x = -3, y = 6
8. x = 5, y = 1
9. x = -2, y = 6
---
1.
3x + 3y = 21
2x - 2y = 6
We can simplify both equations first:
Divide first equation by 3:
→ x + y = 7 → (Equation A)
Divide second equation by 2:
→ x - y = 3 → (Equation B)
Now add Equation A and B:
(x + y) + (x - y) = 7 + 3
→ 2x = 10 → x = 5
Plug x = 5 into Equation A:
5 + y = 7 → y = 2
✔ Check:
3(5)+3(2)=15+6=21 ✔️
2(5)-2(2)=10-4=6 ✔️
---
2.
5x + y = 8
2x + 3y = 13
Use substitution. From first equation:
y = 8 - 5x
Plug into second equation:
2x + 3(8 - 5x) = 13
2x + 24 - 15x = 13
-13x + 24 = 13
-13x = -11 → x = 11/13? Wait — that seems messy. Let me check again.
Wait — maybe I made a mistake. Let’s try elimination instead.
Multiply first equation by 3:
15x + 3y = 24
Second equation: 2x + 3y = 13
Subtract second from first:
(15x + 3y) - (2x + 3y) = 24 - 13
13x = 11 → x = 11/13? Still fraction. But let’s keep going.
Then y = 8 - 5*(11/13) = 8 - 55/13 = (104 - 55)/13 = 49/13
But this feels off — maybe the numbers are meant to be integers? Let me double-check original problem.
Original:
5x + y = 8
2x + 3y = 13
Try plugging in small integer values.
Try x=1: then y=3 → 2(1)+3(3)=2+9=11 ≠13
x=2: y=8-10=-2 → 2(2)+3(-2)=4-6=-2≠13
x=0: y=8 → 0+24=24≠13
x= -1: y=13 → 2(-1)+3(13)= -2+39=37≠13
Hmm. Maybe it’s correct as fractions? But let’s re-solve carefully.
From 5x + y = 8 → y = 8 - 5x
Plug into 2x + 3y = 13:
2x + 3(8 - 5x) = 13
2x + 24 - 15x = 13
-13x = 13 - 24 = -11
x = 11/13
y = 8 - 5*(11/13) = 104/13 - 55/13 = 49/13
So answer is x=11/13, y=49/13 — but that’s unusual for Grade 10. Maybe typo? Or perhaps we proceed.
Wait — let me check if I copied right. Original says:
“2. 5x + y = 8
2x + 3y = 13”
Yes. So unless there’s a typo, we go with fractions.
But let’s hold on — maybe I should do all problems and see pattern. Perhaps some have nice answers.
Actually, let’s assume it’s correct and move on. We’ll write fractional answers where needed.
But wait — let me try solving #2 again with elimination properly.
Eq1: 5x + y = 8
Eq2: 2x + 3y = 13
Multiply Eq1 by 3: 15x + 3y = 24
Keep Eq2: 2x + 3y = 13
Subtract Eq2 from modified Eq1:
(15x + 3y) - (2x + 3y) = 24 - 13
13x = 11 → x = 11/13
Same result. So yes, it’s correct.
But since this is Grade 10, maybe they expect decimal? Or perhaps I misread.
Wait — looking back at image description — user said “image contains task” — but I don’t have image, only text provided. The text says:
“2. 5x + y = 8
2x + 3y = 13”
So we must solve as given.
Proceeding.
x = 11/13, y = 49/13
But let’s write as mixed numbers or decimals? Better as fractions.
Alternatively, maybe the problem was meant to be 5x + y = 9? Then x=1, y=4 → 2+12=14 no. Or 5x+y=7? x=1,y=2 → 2+6=8 no.
I think we have to accept fractions here.
But let’s continue — maybe other problems are nicer.
---
3.
4x - y = 17
2x - 2y = 10
Simplify second equation: divide by 2 → x - y = 5 → y = x - 5
Plug into first:
4x - (x - 5) = 17
4x - x + 5 = 17
3x = 12 → x = 4
Then y = 4 - 5 = -1
Check:
4(4) - (-1) = 16 +1 =17 ✔️
2(4) -2(-1)=8+2=10 ✔️
Good.
---
4.
4x + 3y = 42
3x - y = 12
From second equation: y = 3x - 12
Plug into first:
4x + 3(3x - 12) = 42
4x + 9x - 36 = 42
13x = 78 → x = 6
Then y = 3(6) - 12 = 18 - 12 = 6
Check:
4(6)+3(6)=24+18=42 ✔️
3(6)-6=18-6=12 ✔️
Perfect.
---
5.
3x - 2y = 5
4x + 5y = 45
Use elimination. Make coefficients of y same.
Multiply first by 5: 15x - 10y = 25
Multiply second by 2: 8x + 10y = 90
Add them:
15x -10y +8x +10y = 25+90
23x = 115 → x = 5
Plug into first: 3(5) -2y =5 → 15 -2y=5 → -2y= -10 → y=5
Check:
3(5)-2(5)=15-10=5 ✔️
4(5)+5(5)=20+25=45 ✔️
Great.
---
6.
2x - 3y = 10
4x + 5y = 38
Eliminate x. Multiply first by 2: 4x - 6y = 20
Second: 4x + 5y = 38
Subtract first from second:
(4x +5y) - (4x -6y) = 38 - 20
4x +5y -4x +6y = 18
11y = 18 → y = 18/11
Then from first: 2x -3*(18/11) =10
2x - 54/11 = 10
2x = 10 + 54/11 = 110/11 + 54/11 = 164/11
x = 82/11
Check:
2*(82/11) -3*(18/11) = 164/11 - 54/11 = 110/11 =10 ✔️
4*(82/11) +5*(18/11) = 328/11 + 90/11 = 418/11 = 38 ✔️
So x=82/11, y=18/11
Again fractions — but mathematically correct.
---
7.
x + 5y = 27
3x + 5y = 21
Subtract first from second:
(3x +5y) - (x +5y) = 21 - 27
2x = -6 → x = -3
Plug into first: -3 +5y=27 → 5y=30 → y=6
Check:
-3 +5*6= -3+30=27 ✔️
3*(-3)+5*6= -9+30=21 ✔️
Good.
---
8.
2x - 2y = 8
5x - 3y = 22
Simplify first: divide by 2 → x - y = 4 → x = y + 4
Plug into second:
5(y+4) -3y =22
5y +20 -3y =22
2y =2 → y=1
Then x=1+4=5
Check:
2(5)-2(1)=10-2=8 ✔️
5(5)-3(1)=25-3=22 ✔️
Perfect.
---
9.
2x + 5y = 26
x + 4y = 22
From second: x = 22 - 4y
Plug into first:
2(22 - 4y) +5y =26
44 -8y +5y =26
44 -3y =26
-3y = -18 → y=6
Then x=22 -4*6=22-24= -2
Check:
2(-2)+5(6)= -4+30=26 ✔️
-2 +4*6= -2+24=22 ✔️
Good.
---
Now, let’s list all answers clearly.
Note: Problems 2 and 6 gave fractional answers. Since the worksheet didn’t specify integer solutions, we present exact fractions.
Final Answers:
1. x = 5, y = 2
2. x = 11/13, y = 49/13
3. x = 4, y = -1
4. x = 6, y = 6
5. x = 5, y = 5
6. x = 82/11, y = 18/11
7. x = -3, y = 6
8. x = 5, y = 1
9. x = -2, y = 6
For problem 2 and 6, if decimals are preferred:
2. x ≈ 0.846, y ≈ 3.769
6. x ≈ 7.455, y ≈ 1.636
But since it's math, fractions are better.
However, let me double-check problem 2 — maybe I misread the original.
User wrote:
"2. 5x + y = 8
2x + 3y = 13"
What if it was 5x + y = 9? Then x=1, y=4 → 2+12=14 no.
Or 5x + y = 7? x=1,y=2 → 2+6=8 no.
Or 2x + 3y = 14? Then with x=1,y=3 → 2+9=11 no.
Perhaps it's correct as is.
Similarly for 6: 2x-3y=10, 4x+5y=38 — solution is indeed fractional.
So we'll go with fractions.
Final Answer:
1. x = 5, y = 2
2. x = \frac{11}{13}, y = \frac{49}{13}
3. x = 4, y = -1
4. x = 6, y = 6
5. x = 5, y = 5
6. x = \frac{82}{11}, y = \frac{18}{11}
7. x = -3, y = 6
8. x = 5, y = 1
9. x = -2, y = 6
Parent Tip: Review the logic above to help your child master the concept of gr 10 math worksheet.