Posted by Denis Borris on November 11, 2002 at 07:44:10:
In Reply to: "Prove" 2=1 posted by MathBard on November 11, 2002 at 01:20:11:
: I saw a basic Algebra problem once that gave the illusion that 2=1,
:after doing normal inverse operations and properties of equality steps.
: I know it camoaflagued zero as a variable somehow then divided by that
: variable, but it isn't obvious to the beginner that said variable is actually zero.
:DOES ANYONE KNOW THIS PROBLEM WENT? I can't seem to remember anymore than I have shared. (All the steps need to be understandable to Algebra I students).
Hmmmm....isn't "I can't seem..." something that makes Billy Shakespeare
roll over in his grave? :)
let a = b
aČ = ab
Multiply both sides by a
aČ + aČ - 2ab = ab + aČ - 2ab
Add (aČ - 2ab) to both sides
2(aČ - ab) = aČ - ab
Factor the left, and collect like terms on the right
2 = 1
Divide both sides by (aČ - ab)
Post a Followup