Use the elimination method to solve the linear-quadratic system y = x ^ 2 - 2x - 2y = 2x - 6.

(- 2, - 2) and (- 2, 2)
(2, - 2)
(2, - 2) and (- 2, 2)
(- 2, - 10)

User Icon for Bot GPT 4-o mini Bot GPT 4-o mini answered
1 month ago

To solve the system of equations using the elimination method, we first rewrite the system clearly:

1. \( y = x^2 - 2x - 2 \)
2. \( y = 2x - 6 \)

We can set these two equations equal to each other since they both equal \(y\):

\[
x^2 - 2x - 2 = 2x - 6
\]

Next, we'll move all terms to one side to form a standard quadratic equation:

\[
x^2 - 2x - 2 - 2x + 6 = 0
\]

Combine like terms:

\[
x^2 - 4x + 4 = 0
\]

Next, we can factor the quadratic:

\[
(x - 2)(x - 2) = 0
\]

Thus, we have:

\[
x - 2 = 0 \quad \Rightarrow \quad x = 2
\]

Since this is a repeated root, we only have one value for \(x\) (i.e., \(x = 2\)).

Now we will find the corresponding \(y\) value by substituting \(x = 2\) back into either of the original equations. We'll use the second equation for simplicity:

\[
y = 2(2) - 6
\]
\[
y = 4 - 6
\]
\[
y = -2
\]

Thus, one solution to the system is \((2, -2)\).

Next, we need to check if there are any other solutions. Since we have a quadratic equation, we can see if it may yield any other values by substituting our \(x = 2\) back into the first equation to verify if there might be additional solutions.

Going back to the first equation:

\[
y = x^2 - 2x - 2,
\]

At \(x = 2\):

\[
y = 2^2 - 2(2) - 2
\]
\[
y = 4 - 4 - 2
\]
\[
y = -2,
\]

Verifying for any additional values:

The quadratic equation \(x^2 - 4x + 4 = 0\) only produces one unique solution \(x=2\) which means that the original system only has one solution at \((2, -2)\).

Now, let's check if by symmetry or the nature of the quadratic could yield surfaces through the concept of equal values:

Since we derived it from quadratic roots, recap from primary values of y via substitution of original equations leads us nowhere else.

Thus the final solution set for the given system is:

\[
\text{(2, -2)}
\]

Hence the correct answer from your given choices is:

\((2, -2)\).