Solving with Elimination Practice

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Question
Solve the system of equations.
2x+8y=8

2x−4y=−16
(1 point)
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1 answer

To solve the system of equations using the elimination method, we have the following equations:

  1. \( 2x + 8y = 8 \)
  2. \( 2x - 4y = -16 \)

First, let's align the equations for clarity:

\[ \begin{align*} (1) & \quad 2x + 8y = 8 \ (2) & \quad 2x - 4y = -16 \ \end{align*} \]

Next, we can eliminate \(x\) by subtracting one equation from the other. To do this, we can first multiply equation (2) by -1 so that we can eliminate \(2x\):

\[ -1 \cdot (2x - 4y) = -1 \cdot (-16) \implies -2x + 4y = 16 \]

Now we can rewrite our system:

  1. \( 2x + 8y = 8 \)
  2. \( -2x + 4y = 16 \)

Next, we can add the two equations together:

\[ (2x + 8y) + (-2x + 4y) = 8 + 16 \]

This simplifies to:

\[ 0x + 12y = 24 \]

Thus, we can solve for \(y\):

\[ 12y = 24 \quad \implies \quad y = \frac{24}{12} = 2 \]

Now that we have the value for \(y\), let's substitute \(y = 2\) back into one of the original equations to find \(x\). We'll use equation (1):

\[ 2x + 8(2) = 8 \]

This simplifies to:

\[ 2x + 16 = 8 \]

Now, we isolate \(2x\):

\[ 2x = 8 - 16 \quad \implies \quad 2x = -8 \quad \implies \quad x = -4 \]

Thus, the solution to the system of equations is:

\[ (x, y) = (-4, 2) \]

The final answer is:

\[ \boxed{(-4, 2)} \]