Complete the square to solve the following quadratic equation: x2+2x−8=0 .(1 point) Responses x=−2, x=4 x equals negative 2 , x equals 4 x=−10, x=8 x equals negative 10 , x equals 8 x=2, x=−4 x equals 2 , x equals negative 4 x=10, x=−8

3 answers

To solve the quadratic equation x2+2x8=0 by completing the square, follow these steps:

  1. Move the constant to the right side of the equation: x2+2x=8

  2. To complete the square, take half of the coefficient of x (which is 2), square it, and add it to both sides. Half of 2 is 1, and 12=1: x2+2x+1=8+1 x2+2x+1=9

  3. The left side can now be factored: (x+1)2=9

  4. Now, take the square root of both sides: x+1=3orx+1=3

  5. Solve for x: x+1=3x=2 x+1=3x=4

Thus, the solutions are: x=2andx=4

So, the correct answer is: x equals 2, x equals negative 4.

Complete the square to solve the following quadratic equation: x2−22x+1=15 .(1 point) Responses x=−11+14−−√, −11−14−−√ x equals negative 11 plus Start Root 14 End Root comma negative 11 minus Start Root 14 End Root x=−11+315−−√, −11−315−−√ x equals negative 11 plus 3 Start Root 15 End Root comma negative 11 minus 3 Start Root 15 End Root x=11+14−−√, 11−14−−√ x equals 11 plus Start Root 14 End Root comma 11 minus Start Root 14 End Root x=11+315−−√, 11−315−−√

To solve the given quadratic equation x222x+1=15 by completing the square, we will follow these steps:

  1. Rearrange the equation: Start by moving the constant term from the right side: x222x+115=0 Simplifying gives: x222x14=0

  2. Move the constant to the right side: x222x=14

  3. Complete the square: Take half of the coefficient of x (which is 22), square it, and add it to both sides. Half of 22 is 11, and 112=121: x222x+121=14+121 x222x+121=135

  4. Factor the left side: (x11)2=135

  5. Take the square root of both sides: x11=135orx11=135

  6. Solve for x: x=11+135orx=11135

Now, since 135=915=315, the final solutions are: x=11+315andx=11315

Therefore, the correct response is: x equals 11 plus 3 Start Root 15 End Root, 11 minus 3 Start Root 15 End Root.