Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

a123

(x+3)^2 - (3x-1)^2 = x^3 + 4? i've tried this three times and I still get the wrong answer!

  • 2 years ago
  • 2 years ago

  • This Question is Closed
  1. a123
    Best Response
    You've already chosen the best response.
    Medals 0

    \[(x+3)^2 - (3x - 1)^2 = x^3 + 4\]

    • 2 years ago
  2. a123
    Best Response
    You've already chosen the best response.
    Medals 0

    just to clarify

    • 2 years ago
  3. jim_thompson5910
    Best Response
    You've already chosen the best response.
    Medals 1

    unless you know the cubic formula, your best bet is to use a graphing calculator to find the approximate solutions.

    • 2 years ago
  4. a123
    Best Response
    You've already chosen the best response.
    Medals 0

    we're not allowed to use a calculator. the answer is supposed to come out to be - 2/3

    • 2 years ago
  5. a123
    Best Response
    You've already chosen the best response.
    Medals 0

    but I don't know how to get there

    • 2 years ago
  6. jim_thompson5910
    Best Response
    You've already chosen the best response.
    Medals 1

    ok so there's a typo somewhere in the problem then, my guess is that x^3 is one of the typos

    • 2 years ago
  7. a123
    Best Response
    You've already chosen the best response.
    Medals 0

    wait, I made a mistake typing out the problem. it's actually \[(x+3)^3\] as the first one

    • 2 years ago
  8. jim_thompson5910
    Best Response
    You've already chosen the best response.
    Medals 1

    oh ok thx, one sec

    • 2 years ago
  9. a123
    Best Response
    You've already chosen the best response.
    Medals 0

    so \[(x+3)^3 - (3x - 1)^2 = x^3 + 4\]

    • 2 years ago
  10. jim_thompson5910
    Best Response
    You've already chosen the best response.
    Medals 1

    \[\large (x+3)^3- (3x-1)^2 = x^3 + 4\] \[\large x^3+9x^2+27x+27- (9x^2-6x+1) = x^3 + 4\] \[\large x^3+9x^2+27x+27- 9x^2+6x-1 = x^3 + 4\] \[\large x^3+9x^2+27x+27- 9x^2+6x-1 - x^3 - 4=0\] \[\large 33x+22=0\] \[\large 33x=-22\] \[\large x=-\frac{22}{33}\] \[\large x=-\frac{2}{3}\]

    • 2 years ago
  11. a123
    Best Response
    You've already chosen the best response.
    Medals 0

    thank you! i see exactly where I went wrong.

    • 2 years ago
    • Attachments:

See more questions >>>

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.