Viewing Thread:
"Spot the error"

Here's one for the maths boffins.
See if you can find the error.

Suppose that a = b.

Multiply both sides by a, which gives us a² = ab.

add (a² - 2ab) to both sides to get a² + (a² - 2ab) = ab + (a² - 2ab).

Simplify to get 2(a² - ab) = a² - ab.

Finally divide both sides by a² - ab.

This gives 2 = 1.

Ach bollards!

So much for a bloody engineering degree. I never do read questions properly...

Yeah, but I also said I did better in politics. You could say the same for my maths :^)

Dr Duck wrote:
>
> :^)

hang on, didn't you say you were doing Law?!?

;)

Dr Duck wrote:
> Simon Says wrote:
> Suppose that a = b.
> >
> Simplify to get 2(a² - ab) = a² - ab.
>
>
> Since a=b,
> a²-ab = a² - a² = 0
>
> 2 x 0 = 1 x 0 = 0
>
> :^)

congratulations ;)

Simon Says wrote:
> Suppose that a = b.
>
> Simplify to get 2(a² - ab) = a² - ab.


Since a=b,
a²-ab = a² - a² = 0

2 x 0 = 1 x 0 = 0

:^)

Your Honour wrote:
> Simon Says wrote:
> Here's one for the maths boffins.
> This gives 2 = 1.
>
>
> No, it doesn't, it gives:
>
> 2 = [a²/(a² - ab)] - [ab/(a² - ab)]
>
>
> Because you have to divide each element by a² - ab.

it doesn't make any different because you can add the numerators of fractions with common denomenators.

i.e (2/5) + (3/5) = 5/5

as for the ickle powers, I don't know if there is another way but I copied them from word

I think.

I may be wrong of course...

Anyway, and more importantly, how did you get the little ²? I just copied yours...

Simon Says wrote:
> Here's one for the maths boffins.
> This gives 2 = 1.


No, it doesn't, it gives:

2 = [a²/(a² - ab)] - [ab/(a² - ab)]


Because you have to divide each element by a² - ab.

Here's one for the maths boffins.
See if you can find the error.

Suppose that a = b.

Multiply both sides by a, which gives us a² = ab.

add (a² - 2ab) to both sides to get a² + (a² - 2ab) = ab + (a² - 2ab).

Simplify to get 2(a² - ab) = a² - ab.

Finally divide both sides by a² - ab.

This gives 2 = 1.