A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

(3sqrt(7) -6sqrt(3)) (3sqrt(7) +9sqrt(3)) multiply to solve.

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

    I got -99+9sqrt(21)

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

    1.) 3sqrt(2) * [3 + sqrt(2)] Distribute for each term: 9sqrt(2) + 3sqrt(2)*sqrt(2) (Multiplying like roots cancels it out to the actual number, 2 in this case) 9sqrt(2) + 3*2 9sqrt(2) + 6 2.) 4 + sqrt(20)/2 Assuming that the 2 is being divided into ONLY the sqrt(20)... 4 + 2sqrt(5)/2 (The 2s cancel here because of division) 4 + sqrt(5) In the case that the 2 is being divided into BOTH the 4 and the sqrt(2)... [4 + 2sqrt(5)]/2 2 + sqrt(5) 3.) 12sqrt(18)/3sqrt(2) Again, simplify the roots as much as possible... 12*3sqrt(2)/3sqrt(2) (The 3sqrt(2) cancels because of division) 12 So, your answers are 1.) 9sqrt(2) + 6 2.) 4 + sqrt(5) (or 2 + sqrt(5), depending) 3.) 12

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

    Wow, great explanation!

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

    \[(3\sqrt{7} -6\sqrt3) (3\sqrt7 +9\sqrt3) = 9*7 + 27\sqrt21 - 18\sqrt21 - 54*3 = 63 + 9\sqrt21 - 162 = -99 + 9\sqrt21\]

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

    or that lol

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

    Thanks

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

    so the answer is 63+9sqrt(21-16)

  8. 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.