What is the solution to the system of equations below?


y = one-half x minus 4 and y = negative 2 x minus 9
(–2, –5)
(–2, –3)
(2, –3)
(2, –13)

1 answer

To solve the system of equations, we can set the two expressions for \( y \) equal to each other because they both equal \( y \).

The two equations are:

  1. \( y = \frac{1}{2}x - 4 \) (Equation 1)
  2. \( y = -2x - 9 \) (Equation 2)

Now we'll set them equal to each other:

\[ \frac{1}{2}x - 4 = -2x - 9 \]

To eliminate the fraction, we can multiply every term by 2:

\[ x - 8 = -4x - 18 \]

Next, we'll add \( 4x \) to both sides:

\[ x + 4x - 8 = -18 \]

This simplifies to:

\[ 5x - 8 = -18 \]

Now, add 8 to both sides:

\[ 5x = -10 \]

Divide by 5:

\[ x = -2 \]

Now that we have \( x \), we can substitute it back into one of the original equations to find \( y \). We'll use Equation 1:

\[ y = \frac{1}{2}(-2) - 4 \]

\[ y = -1 - 4 \]

\[ y = -5 \]

Thus, the solution to the system of equations is \( (x, y) = (-2, -5) \).

Verifying with Equation 2:

\[ y = -2(-2) - 9 \]

\[ y = 4 - 9 \]

\[ y = -5 \]

Both equations confirm that the solution is valid.

The answer is \( (-2, -5) \).