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45 votes
45 votes
80 Points, please help!

If using the method of completing the square to solve the quadratic equation x^2-11x-14=0, which number would have to be added to "complete the square"?

80 Points, please help! If using the method of completing the square to solve the-example-1
User Ivan G
by
2.9k points

2 Answers

21 votes
21 votes

Answer:

±√177/2+11/2

Step-by-step explanation:

Use the formula (b/2)^2 in order to create a new term. Solve for x by using this term to complete the square. Exact Form:x=±√177/2+11/2

x=12.15206734…,−1.15206734…

User Edmar
by
3.2k points
12 votes
12 votes

Answer:

30.25

Step-by-step explanation:

Quadratic Equation: x² - 11x - 14 = 0

Number added = (b/2)² = (-11/2)² = 30.25

Solving Steps:

  • x² - 11x = 14

[add both sides by 30.25]

  • x² - 11x + 30.25 = 14 + 30.25

[complete square]

  • (x - 5.5)² = 44.25

[exchange sides]

  • (x - 5.5)² - 44.25 = 0
User Merlincam
by
3.0k points