Algebra

I need help doing this problem, should I not get the same answer with each technique? Please help.

What three techniques can be used to solve a quadratic equation? Demonstrate these techniques on the equation:
2x² + 3x + 1 = 0

  1. 👍 0
  2. 👎 0
  3. 👁 80
asked by Vilma
  1. 1. Factoring (works only in special cases)
    (2x+1)(x+1) = 0
    2x+1=0 or x+1=0
    x = -1/2 or x = -1

    2. completing the square, works all the time
    (I use this method when the coefficient of the square term is 1 and the middle term is even)

    divide by 2
    x^2 + (3/2)x = -1/2
    take 1/2 the coefficient of the middle term, square it and add it to both sides
    x^2 + (3/2)x + 9/16 = -1/2 + 9/16
    (x+ 3/4)^2 = 1/16
    take √ of both sides
    x+3/4 = ± 1/4
    x = -3/4 ± 1/4
    x = -1/2 or x = -1

    3. The quadratic formula, works all the time.
    x = (-3 ± √(9-4(2)(1))/4
    = (-3 ±√1)/4
    = -1/2 or -1

    1. 👍 0
    2. 👎 0
    posted by Reiny

Respond to this Question

First Name

Your Response

Similar Questions

  1. algebra

    Solve the linear equation using any technique you have learned. Name the technique. Check. 3x + 12 = -7x - 28 I know the answer is x = -4 and I know that substitution is the technique that is used, but I can't figure out how to

    asked by lovey on February 21, 2010
  2. Math

    I need help with this problem. The question is : Find the exact value of the following expression. 6*22*5. Use any mental calculation technique you choose. Name the technique you use in each case. Here is what I have: 60*(20+2)*5

    asked by B.B. on June 9, 2009
  3. FACTORING

    I can't figure out how to factor this. I know you use the technique Factor by Grouping. But can someone explain to me how to factor this problem by using factor by grouping technique. Problem: 30x^3 + 18x^2 - 5x - 3. Thanks so

    asked by Miley on January 30, 2008
  4. Math

    Here is the question: Find the exact value of the following expression: 6*22*5. Use any mental calculation technique you choose. Name the technique. Here is what my answer looks like: 6*22*5 (6*5)*2*11 (30*2)*11 60*11=660 I

    asked by B.B. on June 10, 2009
  5. overview of teaching techniques

    which of the following statements is a good technique to use when tutoring a student? (a)''the next problem is easy.you should be able to get it.'' (b)''this next problem is hard,but lets see if you can get it.''(my answer)

    asked by susue on August 25, 2011
  6. Biology

    For many years, humans have used a variety of techniques that have influenced the genetic makeup of organisms. These techniques have led to the production of new varieties of organisms that possess characteristics that are useful

    asked by Joe on February 22, 2009
  7. liturature

    What does the term 'craft technique' mean? Example:"What is one author's craft technique found in this text that makes the writing lively?' See my answer to your question below. =) What is a story with one or more level of

    asked by Sharon on November 8, 2006
  8. Psychology

    Please help! Is this the correct answer. I choose B The person who agrees to a small request initially is more likely later to comply with a larger demand. This describes the a. door-in-the-face-effect. b. foot-in-the-door effect.

    asked by Keller on December 12, 2011
  9. Art

    While discussion the pictures in a book, students ask their teacher many questions about the technique used to create such distinct pictures. Noticing the interest of the students, how can the teacher best address the interest in

    asked by Diana on September 2, 2019
  10. Math

    Which linear technique would be best to solve this problem? 3x/4 + 6 = -12

    asked by lyndse on December 12, 2009

More Similar Questions