1=2?
Let there be 2 variables a and b where, a=b 1. multiply a on both the sides, a^{2}=ab 2. subtract b^2 on both the sides, a^{2}-b^{2}=ab-b^{2} 3. since a^{2}-b^{2}=(a+b)(a-b), (a+b)(a-b)=b(a-b) [taking b common] 4. dividing by (a-b) on both the sides, we get, a+b=b 5. but a=b as given in the first step, b+b=b 2b=b 6. dividing by b on both sides, 2=1 Which step did I make a mistake?
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
The 4th step has a mistake as a=b and thus a-b=0. This means that in this step I divided an expression by 0. But division by 0 is not possible and thus this step contains the mistake.