A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

The perimeter of a semicircle is doubled when the radius is increased by 3. Find the radius of the semicircle.

  • This Question is Open
  1. Vocaloid
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    perimeter of a semicircle is r*pi + 2r so the old perimeter is r*pi + 2r and the new perimeter is (r+3)*pi + 2(r+3) we know that the new perimeter is twice the old perimeter so: 2*(r*pi + 2r) = (r+3)*pi + 2(r+3) solve for r

  2. madhu.mukherjee.946
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    did you understand

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

    \[2(\pi r+2r)=(r+3)\pi +2(r+3)\] does it look like this

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

    yes, do you know where to go from there?

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

    \[\pi r =3\pi - 2r+6\] i end up to this :(

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

    i distributed first

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

    hmm let's take it from the top 2*(r*pi + 2r) = (r+3)*pi + 2(r+3) 2*r*pi + 4r = pi*r + 3*pi + 2r + 6 pi*r + 2r = 3*pi + 6 we can factor r on the left side, and 3 on the right side giving us: r(pi+2) = 3(pi + 2) then we divide both sides by (pi + 2) r = 3 is that clear?

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

    oh, i did not factor... thanks. its now clear to me

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

    uhmmmm can i ask 5 more problems?

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

    sure

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

    Joy is an instructional assistant in one of the college labs. She is on a very tight budget. She loves Jamaican Blue Mountain coffee, but it costs $15 a pound. She decides to blend this with regular coffee beans that costs $1.67 a pound. If she spends $14.25 on 3 pounds of coffee, how many pounds of each did she purchase? Round your answers to two decimal places.

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

    let's let b = number of pounds of blue mountain and r = regular r + b = 3 since there are 3 pounds of coffee 15b + 1.67r = 14.25 know where to go from there?

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

    no :(

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

    sorry

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

    ok, that's fine, no need to apologize we have 2 equations that will help us find what r and b are r + b = 3 15b + 1.67r = 14.25 we can multiply the first equation by (-15), giving us -15r - 15b = -45 now we can put the two equations together again -15r - 15b = -45 15b + 1.67r = 14.25 now we can add the two equations together -15r + 1.67r - 15b + 15b = -45 + 14.25 solve for r

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

    i got 2.31 for r. that is for the regular? what about the pounds of jamaican blue mountain coffee?

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

    i'll multiply r+b=3 to -1.67?

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

    thanks!!! i got it right... thanks a lot! :)))

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

    A patient requires an IV of 0.9% saline solution, also known as normal saline solution. How much distilled water, to the nearest milliliter, must be added to 100 milliliters of a 6 % saline solution to produce normal saline?

  20. 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.