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30 votes
30 votes
6.
2x + 5y = -7
7x + y = -8

User Qtxo
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1 Answer

6 votes
6 votes

Answer:

(- 1, - 1 )

Explanation:

2x + 5y = - 7 → (1)

7x + y = - 8 → (2)

multiplying (2) by - 5 and adding to (1) will eliminate y

- 35x - 5y = 40 → (3)

add (1) and (3) term by term to eliminate y

(- 35x + 2y) + (5y - 5y) = - 7 + 40

- 33x + 0 = 33

- 33x = 33 ( divide both sides by - 33 )

x = - 1

substitute x = - 1 into either of the 2 equations and solve for y

substituting into (1)

2(- 1) + 5y = - 7

- 2 + 5y = - 7 ( add 2 to both sides )

5y = - 5 ( divide both sides by 5 )

y = - 1

solution is (- 1, - 1 )

User Sheilak
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