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Find the solution to the system of equations -3x-9y=18 and 4x+3y=12

1 Answer

2 votes

Answer:

(6, - 4)

Explanation:

Given the 2 equations

- 3x - 9y = 18 → (1)

4x + 3y = 12 → (2)

Multiplying (2) by 3 and adding the result to (1) eliminates the term in y

12x + 9y = 36 → (3)

Add (1) and (3) term by term

(- 3x + 12x) + (- 9y + 9y) = (18 + 36)

9x = 54 ( divide both sides by 9 )

x = 6

Substitute x = 6 into (1) or (2) and solve for y

(2) : 24 + 3y = 12 ( subtract 24 from both sides )

3y = - 12 ( divide both sides by 3 )

y = - 4

Solution is (6, - 4)

User Payel Senapati
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