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Substitution
Elimination +/-
Elimination X
Applying
100

3x - y = 18

y = x - 4

( 7, 3 )

100

- 4x + 3y = -3

4x - 5y = 5

( 0, -1 )

100

5x + 6y = -8

2x + 3y = -5

( 2, -3)

100

5x + 7y = 2 

-2x + 7y = 9

Elimination ( - ); ( -1 , 1)

200

x + 3y = 9

x + y = 1

( - 3, 4 )

200

4x + 6y = 32

3x - 6y = 3

( 5, 2)

200

6a + 2b = 2

4a + 3b = 8

( -1, 4)

200

5x - y = 17

3x + 2y = 5

Substitution; ( 3, -2)

300

y = 2x - 4 

-6x + 3y = -12

Infinite

300

5m - p = 7

7m - p = 11

( 2, 3)

300

2x - y = 4

7x + 3y = 27

( 3, 2)

300

3x + 7y = 4

5x - 7y = -12

Elimination ( + ); ( -1 , 1 )

400

3x + y = 6

4x + 2y = 8

( 2, 0 )

400

8x + 5y = 38

- 8x + 2y = 4

( 1, 6)

400

9a - 2b = -8

- 7a + 3b = 12

( 0 , 4)

400

3x + 4y = 11

2x + y = -1

substitution; ( -3, 5 )

500

2x+ 3y = 4

4x + 6y = 9

No solution

500

- 3x - 8y = -24

3x - 5y = 4.5

( 4 , 1.5)

500

- 4x + 2y = 0

10x + 3y = 8

( 1/2 , 1)

500

3x - 4y = -5

-3x + 2y = 3

Elimination( + ); ( - 1/3 , 1)