perplexus.info :: Numbers : Create the equation

Create the equation (Posted on 2005-05-09)

One solution of the equation (x-a)(x-b)(x-c)(x-d)=25 is x=7.

If a, b, c, and d are different integers, find the value of a+b+c+d

Submitted by Jer

Rating: 2.4286 (7 votes)

Solution: (Hide)

(7-a)(7-b)(7-c)(7-d)=25.
Since each of these factors is different, one of each of them must be -5, -1, 1 and 5.
So the sum
(7-a)+(7-b)+(7-c)+(7-d)=0
28-(a+b+c+d)=0
a+b+c+d=28

Comments: ( You must be logged in to post comments.)

Subject	Author	Date
Solution	Math Man	2015-09-06 19:52:26
Thoughts On A Possible Extension	K Sengupta	2008-07-10 06:17:20
Puzzle Solution	K Sengupta	2008-07-10 06:16:05
Solution	Praneeth	2007-08-20 04:07:21
haaaaaaa	phi	2005-06-22 07:56:45
re: Easy.	morgan	2005-05-14 01:33:49
re: solution	Lisa	2005-05-09 14:24:19
Easy.	Rex	2005-05-09 13:59:08
solution	Lisa	2005-05-09 12:41:17
Morning puzzle	TomM	2005-05-09 10:50:08

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