My Math Forum Help!!

 Algebra Pre-Algebra and Basic Algebra Math Forum

February 11th, 2019, 02:40 PM   #1
Newbie

Joined: Feb 2019
From: Australia

Posts: 1
Thanks: 0

Help!!

Ok, so I've been working on this question for days and nothing has been working.

The requirements are a rule (algebraic formula) for the matchstick pattern (e.g. x= n(n-1) 4n etc.)

Here is the table - PM me for the visual representation.

Item (x)= 1, 2, 3, 4,

Matchsticks (n)= 4, 12, 24, 40,

any help would be much appreciated.

(Just to clarify, 1 item = 4 matchsticks.)
Attached Images
 Screen Shot 2019-02-12 at 9.33.25 am.jpg (5.4 KB, 1 views)

Last edited by skipjack; February 12th, 2019 at 05:04 PM.

 February 11th, 2019, 03:46 PM #2 Math Team     Joined: Jul 2011 From: Texas Posts: 2,947 Thanks: 1555 1 ... 2x2 2 ... 3X4 3 ... 4x6 4 ... 5x8 see a pattern?
 February 11th, 2019, 11:59 PM #3 Global Moderator   Joined: Dec 2006 Posts: 20,747 Thanks: 2133 Hint: evaluate $\displaystyle \frac{\sqrt{2n + 1}}{2}$ for $n\,=$ 4, 12, 24, 40, etc.
 February 12th, 2019, 04:49 AM #4 Math Team   Joined: Oct 2011 From: Ottawa Ontario, Canada Posts: 14,588 Thanks: 1038 Compare to triangulars: 1,3,6,10, ..... 4,12,24,40, .....
 February 12th, 2019, 05:12 AM #5 Senior Member   Joined: Dec 2015 From: somewhere Posts: 536 Thanks: 81 The sequence (n)= 4,12,24,40... etc , is 2n(n+1) . Thanks from NMc
February 12th, 2019, 06:17 AM   #6
Math Team

Joined: Oct 2011

Posts: 14,588
Thanks: 1038

Quote:
 Originally Posted by idontknow The sequence (n)= 4,12,24,40... etc , is 2n(n+1) .
....or TWICE the triangular number formula....

 February 12th, 2019, 08:11 AM #7 Global Moderator   Joined: Dec 2006 Posts: 20,747 Thanks: 2133 Except when it's four times.

 Thread Tools Display Modes Linear Mode

 Contact - Home - Forums - Cryptocurrency Forum - Top