Question

Solve the system of equations.
7x+3y=−25

−7x+9y=−47
(1 point)
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1 answer

To solve the system of equations:

  1. \( 7x + 3y = -25 \)
  2. \( -7x + 9y = -47 \)

we can use the method of elimination or substitution. Here, we will use elimination.

Step 1: Add the equations

If we add both equations together, the \( x \) terms will cancel out:

\[ (7x + 3y) + (-7x + 9y) = -25 + (-47) \]

This simplifies to:

\[ 0x + (3y + 9y) = -72 \]

\[ 12y = -72 \]

Step 2: Solve for \( y \)

Now, divide both sides by 12:

\[ y = \frac{-72}{12} = -6 \]

Step 3: Substitute \( y \) back into one of the original equations

Now that we have \( y \), we can substitute it back into one of the original equations to solve for \( x \). We can use the first equation:

\[ 7x + 3(-6) = -25 \]

\[ 7x - 18 = -25 \]

Step 4: Solve for \( x \)

Add 18 to both sides:

\[ 7x = -25 + 18 \]

\[ 7x = -7 \]

Now, divide both sides by 7:

\[ x = \frac{-7}{7} = -1 \]

Final Step: Write the solution

Thus, the solution to the system of equations is:

\[ (x, y) = (-1, -6) \]

Final answer: \((-1, -6)\)