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Solve the System of Equations using Substitution or Elimination. State your final

answer as an ordered pair (x,y) *
-3x + 10y = -15
5x - 7y = -4

1 Answer

5 votes

Answer:

(- 5, - 3 )

Explanation:

Given the 2 equations

- 3x + 10y = - 15 → (1)

5x - 7y = - 4 → (2)

Multiplying (1) by 5 and (2) by 3 and adding the result, eliminates the x- term.

- 15x + 50y = - 75 → (3)

15x - 21y = - 12 → (4)

Add (3) and (4) term by term to eliminate x, that is

29y = - 87 ( divide both sides by 29 )

y = - 3

Substitute y = - 3 into either of the 2 equations and solve for x

Substituting into (1)

- 3x + 10(- 3) = - 15

- 3x - 30 = - 15 ( add 30 to both sides )

- 3x = 15 ( divide both sides by - 3 )

x = - 5

solution is (- 5, - 3 )

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