Translating word problems  TOPIC_SOLVED

Simplificatation, evaluation, linear equations, linear graphs, linear inequalities, basic word problems, etc.

Translating word problems

Postby Rawshark on Tue Nov 02, 2010 11:49 pm

I read the article on this site on the topic of translating word problems, as well as the part of my math book on it, but I've got a few problems that I just can't seem to translate. Could anyone help, please?

1st problem:
The sum of two numbers is 42. One number plus 2 times the other number is 57. What are the two numbers?

My math teacher helped me translate it, and he said that it would be written as 57=(42-y)-2y, but I think he made a mistake translating it or I did in solving it, because I keep coming up with y = -5 and the answer key said it should be y = 15

Here's how I tried to do it:
57 = (42-y) - 2y
57 = 42 - 3y
15 = 3y
-5 = y

Does anybody know what went wrong here?

And if you're not too sick of me by now, I have another word problem that I really can't translate at all.

2nd problem:
The difference between two numbers is -38. Two times the smaller number minus five times the larger number is -217. What are the two numbers?

Any help would be greatly appreciated, and sorry for asking you guys to help me with all this at once. ^^;
Rawshark
 
Posts: 2
Joined: Tue Nov 02, 2010 8:46 pm

Sponsor

Sponsor
 

  TOPIC_SOLVED

Postby stapel_eliz on Wed Nov 03, 2010 12:23 am

Rawshark wrote:1st problem: The sum of two numbers is 42. One number plus 2 times the other number is 57. What are the two numbers?

My math teacher helped me translate it, and he said that it would be written as 57=(42-y)-2y....

If you're working with "plus", why is there a "minus" sign on the right-hand side of the equation? :wink:

Rawshark wrote:2nd problem: The difference between two numbers is -38. Two times the smaller number minus five times the larger number is -217. What are the two numbers?

Use the same translation technique as you used for the other "number" exercise:

. . . . .one number: x
. . . . .other number: y
. . . . .difference: x - y = -38

...so the "other number" may be stated as:

. . . . .x + 38 = y

Since x - y was negative, then y is the "larger" number, in addition to being the "other" number. Translate "2 times (smaller) minus 5 times (larger) is -217" into an equation. Solve for x. Back-solve for y. 8-)
User avatar
stapel_eliz
 
Posts: 1718
Joined: Mon Dec 08, 2008 4:22 pm

Re: Translating word problems

Postby Rawshark on Wed Nov 03, 2010 12:52 am

Wow! Thank you so much! :D I think I get it now.

stapel_eliz wrote: If you're working with "plus", why is there a "minus" sign on the right-hand side of the equation? :wink:


Oh, jeez, I can't believe I missed that. :shock:

Thank you again! You helped me a lot.
Rawshark
 
Posts: 2
Joined: Tue Nov 02, 2010 8:46 pm


Return to Beginning Algebra