A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

The given equation involves a power of the variable. Find all real solutions of the equation. 8x^2-64=0

  • This Question is Closed
  1. slaaibak
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    8(x^2 - 8)=0 x=2sqrt(2) or x = -2sqrt(2)

  2. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    okay. can you show me what you did there? i'm having real trouble understanding this

  3. slaaibak
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    you first take out the common factor, which is 8: 8(x^2 - 8) = 0 then you use the difference of squares principle: 8(x-sqrt(8))(x+sqrt(8))=0 then x = sqrt(8) or x= -sqrt(8) simplified it's x=2sqrt(2) or x = -2sqrt(2)

  4. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[8x^2-64=0\] add 64 to both sides \[8x^2=64\] divide both sides by 8 \[x^2=8\] take the square root \[x=\pm\sqrt{8}=\pm2\sqrt{2}\]

  5. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i think it's coming to me... i get where you get the common factor, then the difference of squares is giving me trouble... but i see what you are doing...

  6. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    and since \[8=4\times 2\] \[\sqrt{8}=\sqrt{4}\times \sqrt{2}=2\sqrt{2}\]

  7. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    how do you know the 2(sqrt)2?? that is really throwing me for a loop.

  8. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    why isn't the square root of 8 just 2?

  9. 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.