Quantcast

A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

burhan101

  • 2 years ago

Solve for x

  • This Question is Closed
  1. burhan101
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\huge (5)(8)^{(x+2)} = 5^{7x}\]

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

    \[5 \dot\ 8^{x+2} = 5^{7x} \\ 5 \dot\ 8^x 8^2 = \left(5{^7}\right)^x \\5 \dot\ 8^2 = \frac{\left(5{^7}\right)^x}{8^x} \\5 \dot\ 64 = \left(\frac{5^7}{8}\right)^x \\320 = \left(\frac{5^7}{8}\right)^x \] Take logs of both sides and finish simplifying

  3. burhan101
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1359086666173:dw|

  4. burhan101
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    this is what i'm getting, but it is wrong

  5. burhan101
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    wait, we're we sipposed to take the log of both sides?

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

    \[\ln(320) = \ln\left(\left(\frac{5^7}{8}\right)^x\right) \\\ln(320) = x \ln\left(\frac{5^7}{8}\right) \\\frac{\ln(320)}{\ln\left(\frac{5^7}{8}\right)} = x \\\frac{\ln(320)}{\ln5^7 - \ln2^3} = x \\\frac{\ln(320)}{7\ln5 - 3\ln2} = x\]

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

    Uh, ya....logs of both sides. What you do to one side, you do to the other side.

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

    The last two lines, either form, is what you want.

  9. burhan101
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    okay thanks !

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

    By the way, don't forget that you are isolating x bro. Don't confuse the numerator and the denominator.

  11. burhan101
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yeah i know but im getting a weird answer idk why -.-

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

    You should have gotten what I got above. And if you're approximating, you should get x ≈ 0.628

  13. burhan101
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    1 Attachment
  14. Hero
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    You did not isolate x properly bro.

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

    Take a look at your second to last step.

  16. burhan101
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ohhh, i figured it. i flipped it

  17. burhan101
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    got it ! thanks man :)

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

    Wow....bro

  19. 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.