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Solve the system by substitution
5x+y=-14
5x- 3y=2

User Mcveat
by
8.5k points

1 Answer

3 votes

Answer:

x = -2, y = -4, or (-2, -4).

Explanation:

5x + y = -14

5x - 3y = 2

If we look at the first equation, we can see that y can be easily isolated.

5x + y = -14

Subtract 5x from both sides.

y = -5x - 14

Now we have a variable that we can plug into the second equation.

5x - 3y = 2

5x - 3(-5x - 14) = 2

Distribute the -3 across each term in the parentheses.

5x + 15x + 42 = 2

Combine like terms.

20x + 42 = 2

Subtract 42 from both sides.

20x = -40

Divide both sides by 20 to isolate x.

x = -2

Plug in x = -2 back into one of the equations to find y.

y = -5x - 14

y = -5(-2) - 14

Multiply.

y = 10 - 14

Subtract.

y = -4

Our solution is x = -2, y = -4, or (-2, -4).

Check your answer by plugging both values into one of the equations.

5x - 3y = 2

5(-2) - 3(-4) = 2

-10 + 12 = 2

2 = 2

Your answer is correct.

Hope this helps!

User Amilcar
by
8.4k points

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