Anyone good at maths??

[bucko]

This is kinda strange. I'm not a big maths man myself, but the maths teacher whacked this on the board the other day:

KEY - a^2 is a squared and b^2 is b squared

suppose a = b
so a^2 = ab (multiply both sides by a)
a^2 - b^2 = ab - b^2 (subtract b^2 from both sides)
(a - b)(a + b) = b(a - b) (factorise both sides)
a + b = b (divide both sides by (a - b)
since a = b therefore 2b = b
so 2 = 1 if we divide both sides by b.


kinda weird hey???

Apparently theres something wrong with this mathematically. Does anyone know what it is because i'm supposed to find out...

 

[SP]

WTF.... :shock:


is that something like Maths C :shock:

 

[Blade]

"Anyone good at maths?"


No, but I know someone that is.

I'll let him know about this thread next time I speak with him.

 

[JoeD]

This is just a guess but here goes:

(a - b)(a + b) = b(a - b) (factorise both sides)
a + b = b (divide both sides by (a - b)

the problem breaks down at the highlighted stage. If a=b then a-b = 0.
You can't divide a number by 0 and if you try you get strange results like 1=2

 

[legend]

Kaon, our resident genius should be able to crack this relatively simple equation. :idea:

 

[Green Eye]

JoeD answered this correctly. You can't divide the number by 0... It's an old mathematical anomaly.

 

[Willow_2003]

Oh... the zero thing again...
We had a thread at LWOS about 0... is it a number or not a number? It went on for yonks.
Needless to say, the whole conversation was about nothing.
8)

 

[Trojan Horse]

a=b
a^2=ab
a^2-b^2=ab-b^2
{a-b}{a+b}=b{a-b}
a+b=b

Therefore... a DOES NOT = b Because 2 DOES NOT = 1

 

[bucko]

Thanks JoeD, it looks like you're spot on.

 

[kier]

Ha Ha - that old chestnut!

It's an old weapon in the armoury of the maths teacher.....often put up on the board when you've run out of stuff for the class to do......or when you went out the night before and you haven't prepared anything :shock:

The answer is indeed as Joe said - you can't divide by zero.

 

[bucko]

Cool, does anyone know any other similar problems?? Maybe i can get back at my teacher...

 

[kaon]

Not a fan of Maths? Gee, kids these days. :shock:

 

[bucko]

Well i spose it isn't that bad. Do you know any more similar problems that I can use on my teacher??

 

[kaon]

Well i spose it isn't that bad. Do you know any more similar problems that I can use on my teacher??

I know one or two but they're not really what you would call riddles. If you really want one, try this site

http://www.qbyte.org/puzzles/index.html

 

[JoeD]

Here is a similar type problem I think I can remember:

John drives his car from point A to point B at 50 km/h. How fast would he have to drive back to point A to average 100 km/h for the round trip?

 

[chileman]

Needless to say, the whole conversation was about nothing.
8)

:lol: Cero amigo!

 

[JoeD]

Kaon, those puzzles on the page you posted look like university maths level, probably way over the head of your average high school maths teacher :lol: :lol: :lol:

Mine is more of a trick question. If anyone is still interested here's a hint, the answer is not 150 km/h

 

[chileman]

250????? I think I need a coffee, my brain hurts thinking at this time of the morning :lol:

 

[kaon]

Joe, i think those questions are more for high school students but yeah, i agree that some teachers would struggle with some of them. :roll:


With regards to your question, it would be pretty hard to double the distance as well as doubling your average speed. Not unless you get back in no time. ;-)

 

[Green Eye]

Here is a similar type problem I think I can remember:

John drives his car from point A to point B at 50 km/h. How fast would he have to drive back to point A to average 100 km/h for the round trip?

Instantaneously....

BOOYAH!!!