solve the following system by substitution 3x - 2y
= -9 2x + y = 1

Question

Asked 2/21/2013 8:41:44 PM

Updated 11/29/2017 8:35:29 AM

2 Answers/Comments

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OxTornado007|Points 6709|

Question

Asked 2/21/2013 8:41:44 PM

Updated 11/29/2017 8:35:29 AM

2 Answers/Comments

This conversation has been flagged as incorrect.

Rating

3

3x - 2y = -9

2x + y = 1

y = -2x + 1

3x - 2(-2x + 1) = -9

3x + 4x - 2 = -9

7x - 2 = -9

7x = -9 + 2

7x = -7

x = -7/7

x = -1

2(-1) + y = 1

-2 + y = 1

y = 1 + 2

y = 3

Solution set: (-1, 3)

2x + y = 1

y = -2x + 1

3x - 2(-2x + 1) = -9

3x + 4x - 2 = -9

7x - 2 = -9

7x = -9 + 2

7x = -7

x = -7/7

x = -1

2(-1) + y = 1

-2 + y = 1

y = 1 + 2

y = 3

Solution set: (-1, 3)

Added 11/29/2017 8:32:43 AM

This answer has been confirmed as correct and helpful.

3

-6x - y = 1

3x - 4y = 31

(-y = 6x + 1)/(-1)

y = -6x - 1

3x - 4(-6x - 1) = 31

3x + 24x + 4 = 31

27x + 4 = 31

27x = 31 - 4

27x = 27

x = 27/27

x = 1

-6(1) - y = 1

-6 - y = 1

-y = 1 + 6

-y = 7

y = -7

Solution set: (1, -7)

3x - 4y = 31

(-y = 6x + 1)/(-1)

y = -6x - 1

3x - 4(-6x - 1) = 31

3x + 24x + 4 = 31

27x + 4 = 31

27x = 31 - 4

27x = 27

x = 27/27

x = 1

-6(1) - y = 1

-6 - y = 1

-y = 1 + 6

-y = 7

y = -7

Solution set: (1, -7)

Added 11/29/2017 8:35:29 AM

This answer has been confirmed as correct and helpful.

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