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Solve the system of linear equations. 3x + 5y = −2 2x − y = 3 A) (1, 1) B) (−1, 1) C) (1, −1) D) (−1, −1)

User Allenwoot
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1 Answer

7 votes
7 votes

Answer:

x = 1, y = -1 so C)

Explanation:

Solve the following system:

{5 y + 3 x = -2 | (equation 1)

-y + 2 x = 3 | (equation 2)

Subtract 2/3 × (equation 1) from equation 2:

{3 x + 5 y = -2 | (equation 1)

0 x - (13 y)/3 = 13/3 | (equation 2)

Multiply equation 2 by 3/13:

{3 x + 5 y = -2 | (equation 1)

0 x - y = 1 | (equation 2)

Multiply equation 2 by -1:

{3 x + 5 y = -2 | (equation 1)

0 x + y = -1 | (equation 2)

Subtract 5 × (equation 2) from equation 1:

{3 x + 0 y = 3 | (equation 1)

0 x + y = -1 | (equation 2)

Divide equation 1 by 3:

{x + 0 y = 1 | (equation 1)

0 x + y = -1 | (equation 2)

Collect results:

Answer: {x = 1, y = -1

User Txyoji
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