Use the elimination method to solve the linear-quadratic system y=x2−2x−2, y=2x−6.(1 point)%0D%0AResponses%0D%0A%0D%0A(2,−2)%0D%0Aleft parenthesis 2 comma negative 2 right parenthesis%0D%0A%0D%0A(−2,−2) and (−2,2)%0D%0A left parenthesis negative 2 comma negative 2 right parenthesis and left parenthesis negative 2 comma 2 right parenthesis%0D%0A%0D%0A(2,−2) and (−2,2)%0D%0Aleft parenthesis 2 comma negative 2 right parenthesis and left parenthesis negative 2 comma 2 right parenthesis%0D%0A%0D%0A(−2,−10)

1 answer

To solve the linear-quadratic system using the elimination method, we have the following equations:

  1. y=x22x2 (quadratic equation)
  2. y=2x6 (linear equation)

Since both equations are equal to y, we can set them equal to each other:

x22x2=2x6

Now, let's move all terms to one side of the equation:

x22x22x+6=0

This simplifies to:

x24x+4=0

Next, factor the quadratic:

(x2)2=0

This implies:

x2=0x=2

Now we will substitute x=2 into the linear equation to find y:

y=2(2)6=46=2

Thus, we have one solution:

(2,2)

Now, let's check if there are any other solutions by substituting y=2x6 into the quadratic equation again. Since we found (2,2), we can check for a possible repeat:

  1. Substitute y into the quadratic: 2x6=x22x2
    • Rearranging gives us: x24x+4=0(x2)2=0

We already established that the quadratic equation has a double root at x=2 with y=2. This means the only solution for the system is:

(2,2)

Hence, the answer is:

(2, −2)