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Use the substitution method to solve the following system of equations:

4x − y = 3
7x − 9y = −2

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User Mohammad Fazeli
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2 Answers

30 votes
30 votes

Answer:(4x - y = 3) * 9

36x - 9y = 27

7x - 9y = -2

29x = 29

x = 1

y = 4*1 - 3

y = 1

Step-by-step explanation:i dont know what kibble is

User Xavier Egea
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2.9k points
16 votes
16 votes

Answer:

(1, 1 )

Explanation:

4x - y = 3 ( add y to both sides )

4x = y + 3 ( subtract 3 from both sides )

4x - 3 = y → (1)

7x - 9y = - 2 → (2)

Substitute y = 4x - 3 into (2)

7x - 9(4x - 3) = - 2 ← distribute parenthesis and simplify left side

7x - 36x + 27 = - 2

- 29x + 27 = - 2 ( subtract 27 from both sides )

- 29x = - 29 ( divide both sides by - 29 )

x = 1

Substitute x = 1 into (1)

4(1) - 3 = y

4 - 3 = y

1 = y

solution is (1, 1 )

User Paul Fultz II
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