Friday, February 17, 2012

Algebra Worksheet 05: Solving Equations by Factoring Discussion Board

Algebra Worksheet 05: Solving Equations by Factoring
http://erhsnyc.org/ourpages/auto/2012/2/16/48947410/Algebra%20Worksheet%2005_Solving%20Equations%20by%20Factoring.pdf 

2 comments:

  1. *** The following questions are forwarded from a school email ***

    I'm having trouble factoring:

    15x^2+8x-12=0

    8x^2-6x+1=0

    16x^2+25=0

    Thank you

    ReplyDelete
    Replies
    1. Worksheet_05

      Lesson -
      1-5) -16x^2+25=0
      16x^2 - 25 = 0
      Apply A^2 - B^2 = (A + B)(A - B)
      (4x + 5)(4x - 5) = 0
      4x + 5 = 0, or
      4x - 5 = 0
      x = -5/4, 5/4

      * Your original question, 16x^2+25=0, has no solution, since 16x^2 cannot be negative.

      Homework -
      c) 8x^2-6x+1=0
      4x -1
      2x -1
      (4x - 1)(2x - 1) = 0
      4x - 1 = 0, or
      2x - 1 = 0
      x = 1/4, 1/2

      e) 15x^2+8x-12=0
      5x +6
      3x -2
      (5x + 6)(3x - 2) = 0
      5x + 6 =0, or
      3x - 2 = 0
      x = -6/5, 2/3

      Delete