A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 5 years ago
the reciprocal of 4 plus the reciprocal of 5 is the reciprocal of what number?
anonymous
 5 years ago
the reciprocal of 4 plus the reciprocal of 5 is the reciprocal of what number?

This Question is Closed

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0can you please show me how you came up with that answer step by step?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Don't you have a math book or something to teach you how to add fractions? 1/4+1/5, their lowest common denominator is 20, so you multiple 1/4 by 5/5 and 1/5 by 4/4 to get 5/20+4/20

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0The answer should actually be 20/9. The way the question is worded, you want the reciprocal of 9/20. In general, these word problems require a bit of set up. Let x be the number you’re looking for. Then the reciprocal of the number is 1/x. The reciprocal of 4 is 1/4 and the reciprocal of 5 is 1/5. So the problem says that 1/4 + 1/5 = 1/x. Adding the fractions as flyingpigg showed above, we see that 9/20 = 1/x, which is the reciprocal of x. But if 9/20 is the reciprocal of x, then x itself must be 20/9.
Ask your own question
Sign UpFind more explanations on OpenStudy
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
 Engagement 19 Mad Hatter
 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.