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Solve using elimination -x+4y=-19 -3x+3y=6

User Antishok
by
6.1k points

1 Answer

5 votes

Answer:x = -9, y = -7

Explanation:

Equation 1) -x + 4y = -19

Equation 2) -3x + 3y = 6

Multiply ALL of equation 1 by 3 so that both equations include -3x in it.

1) 3(-x + 4y = -19)

Simplify.-3x + 12y = -57 → equation 3

Now, subtract equation 3 from equation 2.

-3x + 12y = -57

(-)-3x + 3y = 6

Simplify.

9y = -63

Divide both sides by 9.

9y ÷ 9 = -63 ÷ 9

Simplify.

y = -7

Now that we have the value for y, simply plug in -7 for y into equation 1.

1) -x + 4y = -19-x + 4(-7) = -19

Simplify.-x - 28 = -19

Add 28 to both sides of the equal sign.

-x - 28 + 28 = -19 + 28

Simplify.-x = 9

Divide both sides by -1.x = -9

Now we know that : x = -9, y = -7

To check our work, simply plug in -9 for x and -7 for y into equation 1.

1) -x + 4y = -19-(-9) + 4(-7) = -19

Simplify.

9 - 28 = -19-19 = -19

Therefore, x = -9, y = -7

Hope this helped! :)

User Krzydyn
by
6.7k points
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