Mind Bender # 15 : Solution
The challenge in the last Mind Bender was to calculate the value of “X” in the following equation …
This time, there were a number of people who came up with the correct answer: Ron Drewitz, Daniel Hayden, Dominic Gatling, John Murphy, Margaret, Elka Melman, Tracey Bryan, Matt, Geoff and Vince Psaradakis.
So, well done to you all.
The secret is to square both sides, so that you then have …
However, we actually started out knowing that …
So we can now make a simple substitution, as follows …
15 June, 2008 at 4:06 pm
I think you have made an error when you squared the left side of the equation.
17 June, 2008 at 1:33 pm
Alan — I think you’ll find what I’ve done is correct.
You see, when you Square the Square Root of “X” … you actually end up back with “X” (and, in this case, together with the re-occurring component as well).
From there, you’re able to substitute for the re-occurring component … which we know to equal “2”.