A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

iwillrektyou

  • one year ago

Help on quadratic equations! Solve 3x^2 + 18x + 15 = 0 by completing the square. 3(x + 3)2 = 6; x = −3 + sqrt2, x = −3 − sqrt2 3(x + 9)2 = 12; x = −11, x = −7 3(x + 3)2 = 12; x = −5, x = −1 3(x + 9)2 = 228; x = −9 + sqrt 76, x = −9 − sqrt 76

  • This Question is Closed
  1. iwillrektyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I did it, but I got something wrong. Here is my work:

  2. misty1212
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    HI!!

  3. pooja195
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Find the GCF of all 3 numbers first.

  4. misty1212
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    divide by 3 first

  5. iwillrektyou
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    3x^2 + 18x + 15 = 0 (3x^2 + 18x) + 15 = 0 3(x^2 + 6x) + 15 = 0 3(x^2 + 6x + 9) + 15 = 0 Then, to make it equal: 3(x^2 + 6x + 9) + 15 - 3(9) = 0 3(x^2 + 6x + 9) -12 = 0 3(x+3)^2 - 12 = 0 +12 +12 3(x+3) = 12 Divide 3 on both sides --> x + 3 = 4

  6. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.