SOLUTION: Use completing the square to solve x�+8x-11=0

Question 173222: Use completing the square to solve x�+8x-11=0
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!

Start with the given left side of the given equation.

Take half of the coefficient to get . In other words, .

Now square to get . In other words,

Now add and subtract . Make sure to place this after the "x" term. Notice how . So the expression is not changed.

Group the first three terms.

Factor to get .

Combine like terms.

So after completing the square, transforms to . So .

So is equivalent to .

------------------------------------------------------------

Start with the given equation.

Add to both sides.

Combine like terms.

Take the square root of both sides.

or Break up the "plus/minus" to form two equations.

or Simplify the square root.

or Subtract from both sides.

--------------------------------------

Answer:

So the solutions are or .

RELATED QUESTIONS
Solve by completing the square:... (answered by Earlsdon)

Solve by completing the square: x^2 + 8x-3 = 0 (answered by Cintchr)

Solve by completing the square... (answered by stanbon)

Solve by completing the square: x^2 + 8x + 13 =... (answered by josmiceli)

Solve by completing the square: x^2 + 8x + 13 = 0 (answered by J2R2R)

solve by completing the square x^2 + 8x - 9 = 0 (answered by scott8148)

x^2-8x+9=0 solve by "completing the... (answered by richard1234)

Solve by completing the square x^2-8x+15=0 (answered by josgarithmetic)

x^2-8x+11=0 Solve the equation by completing the... (answered by edjones)