Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: math question - need help
Replies: 2   Last Post: Oct 21, 2011 8:22 PM

 Messages: [ Previous | Next ]
 Ben Brink Posts: 201 From: Rosenberg, TX Registered: 11/11/06
RE: math question - need help
Posted: Oct 21, 2011 8:22 PM
 att1.html (1.4 K)

Dave,
When x = y, the conditions imply that k = x and k = 2y. Therefore 2y = y, so x = y = 0.
For x > y, I'm getting x = [-5 +/ sqrt(593)]/2, so do we get two intervals for y?
In general x = [-11 +/ sqrt(289 + 6k)]/2. If x < y we can replace k by 2y and solve for y in terms of x. I can't see what we do with that either.
Thanks and will be waiting for what others find.
Ben

> Date: Fri, 21 Oct 2011 09:31:11 -0400
> From: discussions@mathforum.org
> To: discretemath@mathforum.org
> Subject: math question - need help
>
> I received this question and I have no clue how to go about answering it. Any help or guidance would be appreciated. there is a + sign with a circle around it, never been taught that before.
>
> x + (with cirlce around it) y = (x +7)(x + 4) - 6k. If x is greater than or equal to y, then k = x. If x is less than or equal to y, then k = 2y. If x + (with cirlce around it) y = 170, find all distinct possible values of y.
>
> I don't even know where to begin.

Date Subject Author
10/21/11 dave
10/21/11 Ed Wall
10/21/11 Ben Brink