Questions: Find the ordered pair solutions for the system of equations.
[
left
y=x^2-4 x-5
y=-x-7
right.
]
Transcript text: Find the ordered pair solutions for the system of equations.
\[
\left\{\begin{array}{c}
y=x^{2}-4 x-5 \\
y=-x-7
\end{array}\right.
\]
Solution
Solution Steps
To find the ordered pair solutions for the given system of equations, we need to solve the equations simultaneously. We can do this by substituting the expression for \( y \) from the second equation into the first equation and solving for \( x \). Once we have the values of \( x \), we can substitute them back into either equation to find the corresponding \( y \) values.
Step 1: Set Up the System of Equations
We are given the system of equations:
\[
\begin{cases}
y = x^2 - 4x - 5 \\
y = -x - 7
\end{cases}
\]
Step 2: Substitute the Second Equation into the First
Substitute \( y = -x - 7 \) into \( y = x^2 - 4x - 5 \):
\[
-x - 7 = x^2 - 4x - 5
\]
Step 3: Rearrange and Simplify the Equation
Rearrange the equation to form a standard quadratic equation:
\[
x^2 - 4x - 5 + x + 7 = 0
\]
\[
x^2 - 3x + 2 = 0
\]
Step 4: Solve the Quadratic Equation
Solve the quadratic equation \( x^2 - 3x + 2 = 0 \):
\[
(x - 1)(x - 2) = 0
\]
Thus, the solutions for \( x \) are:
\[
x = 1 \quad \text{and} \quad x = 2
\]
Step 5: Find the Corresponding \( y \) Values
Substitute \( x = 1 \) and \( x = 2 \) back into \( y = -x - 7 \) to find the corresponding \( y \) values:
\[
\text{For } x = 1: \quad y = -1 - 7 = -8
\]
\[
\text{For } x = 2: \quad y = -2 - 7 = -9
\]