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40x−3y=78.5 ,−20x+y=−38.5 pls help

User Tanatach
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1 Answer

2 votes

Answer:

x = 1.85, y = - 1.5

Explanation:

Given the 2 equations

40x - 3y = 78.5 → (1)

- 20x + y = - 38.5 → (2)

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

- 60x + 3y = - 115.5 → (3)

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

- 20x = - 37 ( divide both sides by - 20 )

x = 1.85

Substitute x = 1.85 into either of the 2 equations and solve for x

Substituting into (2)

- 20(1.85) + y = - 38.5, that is

- 37 + y = - 38.5 ( add 37 to both sides )

y = - 1.5

User Xgrimau
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