# S.O.S. Mathematics CyberBoard

Your Resource for mathematics help on the web!
 It is currently Sat, 25 May 2013 19:35:22 UTC

 All times are UTC [ DST ]

 Page 1 of 1 [ 7 posts ]
 Print view Previous topic | Next topic
Author Message
 Post subject: Find missing OperationPosted: Tue, 6 Dec 2011 05:04:41 UTC
 S.O.S. Oldtimer

Joined: Tue, 30 Dec 2008 20:37:56 UTC
Posts: 205
Location: Accra,Ghana
If ∆ is an operation such that,
a ∆ b = ab + a – b, what does 4 ∆ 8 =?

How best can I approach this question?

Top

 Post subject: Re: Find missing OperationPosted: Tue, 6 Dec 2011 05:06:37 UTC
 Moderator

Joined: Wed, 30 Mar 2005 04:25:14 UTC
Posts: 12103
Location: Austin, TX
Kodwo wrote:
If ∆ is an operation such that,
a ∆ b = ab + a – b, what does 4 ∆ 8 =?

How best can I approach this question?

Just do the operation, a=4, b=8, so you need to calculate (4)(8)+4-8. . .

_________________
(\ /)
(O.o)
(> <)
This is Bunny. Copy Bunny into your signature to help him on his way to world domination

Top

 Post subject: Re: Find missing OperationPosted: Tue, 6 Dec 2011 18:25:46 UTC
 S.O.S. Oldtimer

Joined: Tue, 30 Dec 2008 20:37:56 UTC
Posts: 205
Location: Accra,Ghana
Kodwo wrote:
If ∆ is an operation such that,
a ∆ b = ab + a – b, what does 4 ∆ 8 =?

How best can I approach this question?

Just do the operation, a=4, b=8, so you need to calculate (4)(8)+4-8. . .

4 ∆ 8 = (4)(8) + 4 - 8
4 ∆ 8 = 28
But I believe what the question is asking for is whether ∆ stands for plus,minus,division,multiplication?

Top

 Post subject: Re: Find missing OperationPosted: Tue, 6 Dec 2011 19:19:52 UTC
 Member of the 'S.O.S. Math' Hall of Fame

Joined: Mon, 19 May 2003 19:55:19 UTC
Posts: 7951
Location: Lexington, MA
Hello, Kodwo!

Quote:
If ∆ is an operation such that: a ∆ b = ab + a – b,
what does 4 ∆ 8 = ?

The operation has been defined.

Top

 Post subject: Re: Find missing OperationPosted: Tue, 6 Dec 2011 20:01:13 UTC
 Member of the 'S.O.S. Math' Hall of Fame

Joined: Mon, 19 May 2003 19:55:19 UTC
Posts: 7951
Location: Lexington, MA
Hello again, Kodwo!

Kodwo wrote:
But I believe what the question is asking for is whether ∆ stands for plus, minus, division, multiplication.

If so, the answer is: . stands for a multiplcation, an addition and a subtraction.

No, it is asking for the value of

Top

 Post subject: Re: Find missing OperationPosted: Tue, 6 Dec 2011 20:26:47 UTC
 S.O.S. Oldtimer

Joined: Tue, 30 Dec 2008 20:37:56 UTC
Posts: 205
Location: Accra,Ghana
Hi Soroban,

The answer is 28.I was looking for something else(what delta stood for.But I guess the question did not ask for that)

Top

 Post subject: Re: Find missing OperationPosted: Tue, 6 Dec 2011 23:34:30 UTC
 Moderator

Joined: Wed, 30 Mar 2005 04:25:14 UTC
Posts: 12103
Location: Austin, TX
Kodwo wrote:
Hi Soroban,

The answer is 28.I was looking for something else(what delta stood for.But I guess the question did not ask for that)

Indeed it doesn't, that's part of the point of it, it defines , so it doesn't make much sense to ask for it after they just gave it to you.

_________________
(\ /)
(O.o)
(> <)
This is Bunny. Copy Bunny into your signature to help him on his way to world domination

Top

 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Page 1 of 1 [ 7 posts ]

 All times are UTC [ DST ]

#### Who is online

Users browsing this forum: No registered users

 You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forum

Search for:
 Jump to:  Select a forum ------------------ High School and College Mathematics    Algebra    Geometry and Trigonometry    Calculus    Matrix Algebra    Differential Equations    Probability and Statistics    Proposed Problems Applications    Physics, Chemistry, Engineering, etc.    Computer Science    Math for Business and Economics Advanced Mathematics    Foundations    Algebra and Number Theory    Analysis and Topology    Applied Mathematics    Other Topics in Advanced Mathematics Other Topics    Administrator Announcements    Comments and Suggestions for S.O.S. Math    Posting Math Formulas with LaTeX    Miscellaneous