Consider the following system of equations: 13x + y = 3 2y = −23x + 10 Solve the system of equations using the elimination method. Be sure to show all of your work to earn full points. (5 points)

1 answer

To solve the given system of equations using the elimination method, we start with the two equations:

  1. \( 13x + y = 3 \)
  2. \( 2y = -23x + 10 \)

First, let's rearrange equation (2) to solve for \(y\):

\[ 2y = -23x + 10 \]

To isolate \(y\), divide the entire equation by 2:

\[ y = -\frac{23}{2}x + 5 \]

Now we have:

  1. \( 13x + y = 3 \)
  2. \( y = -\frac{23}{2}x + 5 \)

Next, we will substitute equation (2) into equation (1) to eliminate \(y\):

Substituting for \(y\) in equation (1):

\[ 13x + \left(-\frac{23}{2}x + 5\right) = 3 \]

Now, simplify the equation:

\[ 13x - \frac{23}{2}x + 5 = 3 \]

To combine the terms involving \( x \), let's convert \( 13x \) into a fraction:

\[ 13x = \frac{26}{2}x \]

Now the equation becomes:

\[ \frac{26}{2}x - \frac{23}{2}x + 5 = 3 \]

Combine the \( x \) terms:

\[ \frac{26 - 23}{2} x + 5 = 3 \]

Simplifying that gives:

\[ \frac{3}{2} x + 5 = 3 \]

Next, isolate \( \frac{3}{2} x \):

\[ \frac{3}{2} x = 3 - 5 \]

\[ \frac{3}{2} x = -2 \]

To solve for \( x \), multiply both sides by the reciprocal of \( \frac{3}{2} \):

\[ x = -2 \cdot \frac{2}{3} \]

\[ x = -\frac{4}{3} \]

Now that we have \( x \), we substitute it back into one of the original equations to find \( y \). Using equation (1):

\[ 13\left(-\frac{4}{3}\right) + y = 3 \]

Calculating \( 13(-\frac{4}{3}) \):

\[ -\frac{52}{3} + y = 3 \]

Next, convert \(3\) into a fraction with a denominator of 3:

\[ 3 = \frac{9}{3} \]

Now the equation looks like this:

\[ -\frac{52}{3} + y = \frac{9}{3} \]

Isolating \(y\):

\[ y = \frac{9}{3} + \frac{52}{3} \]

\[ y = \frac{9 + 52}{3} \]

\[ y = \frac{61}{3} \]

Thus, the solution to the system of equations is:

\[ x = -\frac{4}{3} \]
\[ y = \frac{61}{3} \]

We can summarize the solution as:

Solution: \[ \left( x, y \right) = \left( -\frac{4}{3}, \frac{61}{3} \right) \]