Solve.

3x + 7y = –11
5x + 7y = 5

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1 answer

To solve the system of equations:

  1. \( 3x + 7y = -11 \) (Equation 1)
  2. \( 5x + 7y = 5 \) (Equation 2)

We can start by eliminating one of the variables. We can subtract Equation 1 from Equation 2 to eliminate \( y \).

Step 1: Eliminate \( y \)

Subtract Equation 1 from Equation 2:

\[ (5x + 7y) - (3x + 7y) = 5 - (-11) \] This simplifies to:

\[ 5x - 3x = 5 + 11 \] \[ 2x = 16 \]

Step 2: Solve for \( x \)

Divide both sides by 2:

\[ x = 8 \]

Step 3: Substitute \( x \) back into one of the equations to find \( y \)

We can use Equation 1:

\[ 3(8) + 7y = -11 \] \[ 24 + 7y = -11 \]

Now, subtract 24 from both sides:

\[ 7y = -11 - 24 \] \[ 7y = -35 \]

Divide by 7:

\[ y = -5 \]

Final Solution:

The solution to the system of equations is:

\[ (x, y) = (8, -5) \]