Mathematics
08.02.2023 08:51
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Use the addition-subtraction method to solve each of the following systems of equations.

Use the addition-subtraction method to solve each of the following systems of equations.

1. 4x + 3y = 17 and 5x – 3y = 1

2. –5m + 6n = –8 and –5m + 8n = 6

3. 2x – 7y = –9 and 6x + 7y = 57

4. 5p – 4q = 3 and –5p – 4q = 13

5. 6c + d = 12 and c – d = 2

the best answer will receive brainliest .
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annalisamorris0
annalisamorris0
4,5(38 marks)

1. x=2, y=3

2. n=7, m=-6.8

3. x=6, y=3

4. q=-2, p=-1

5. c=2, d=0

Step-by-step explanation:

4x + 3y = 17

5x – 3y = 1

first make it so either x or y can cancel out in both equations, then combine the equations, giving you 9x=18. solve for x, x=2. substitute 2 for x in either equation, 4(2) + 3y = 17. solve for y, 8+3y=17, 3y=9, y=3

–5m + 6n = –8

–5m + 8n = 6

first make it so either m or n can cancel out in both equations, multiply –5m + 6n = –8 by -1, 5m - 6n = 8, then combine the equations, giving you 2n=14. solve for n, n=7. substitute 7 for n in either equation, 5m - 6(7) = 8. solve for m, 5m - 42 = 8, 5m = -34, m = -6.8

2x – 7y = –9

6x + 7y = 57

first make it so either x or y can cancel out in both equations, then combine the equations, giving you 8x=48. solve for x, x=6. substitute 6 for x in either equation, 2(6) – 7y = –9. solve for y, 12 – 7y = –9, –7y = –21, y = 3

5p – 4q = 3

–5p – 4q = 13

first make it so either p or q can cancel out in both equations, then combine the equations, giving you -8q=16. solve for q, q=-2. substitute -2 for q in either equation, 5p – 4(-2) = 3. solve for p, 5p + 8 = 3, 5p = -5, p = -1

6c + d = 12

c – d = 2

first make it so either c or d can cancel out in both equations, then combine the equations, giving you 7c=14. solve for c, c=2. substitute 2 for c in either equation, 6(2) + d = 12. solve for d, 12 + d = 12, d = 0

[EDIT] question 2 is impossible.

bollipard1183
bollipard1183
4,5(22 marks)

y =  - 2 \\ x =  - 2

Step-by-step explanation:

Question

- 5x - 3y = 16  \:  \:  =   1 \\ y = x =   2

Now you can write the 1st equation like this.

- 5x - 3y = 16 \\ x = y \\ so \:  \: you \:  \:  \: can \:  \: write \\  - 5y -  3y = 16  \:  \:  \:  =   3

Now simply Solve the 3rd equation

- 5y - 3y = 16 \\  - 8y = 16 \\  \frac{ - 8y}{ - 8}  =  \frac{16}{ - 8}  \\ y =  - 2

Now replace y as 2 in the 2nd equation like this

y = x \\  - 2 =  - 2

Now let's check whether the answer correct or wrong

- 5x - 3y = 16 \\   -  5 \times  - 2 - 3  \times  - 2 = 16 \\ 10 + 6 = 16 \\ 16 = 16

Yes, the answer is correct

hope this helps you !!

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