how to prove 1+2=4.one maths teacher showed me this ,but i forgot.?

Answer 1

y=x
y+y=y+x
2y=y+x
2y-2x=y-x
2(y-x)=1(y-x) (note:)
so,
2=1....
so
2+2=1+2,
4=1+2
so,1+2=4
note: but as x=y,x-y becomes zero,which is indeterminant....
thus by this only we can prove 1+2=4

Answer 2

I too remember the problem but have forgotten the answer.

It takes two volumes to prove unequivocally that 1+1=2.
It is a relatively simple proof for what you want to do but it isn't 100% logically sound anyway.

The basic idea is to prove that x+y=z for any positive non-zero integer and then substitute the digits you want.

however if
x=y
then x+x=x+y
2x=x+y
2x-2y=x-y
2(x-y)=1(x-y) **
which obviously means that 2=1
therefore 2+2=2+1
4=2+1

there is your proof but if x=y then x-y is 0 which means that the line marked cannot be reduced. negating the proof. however it is a good party trick as nobody notices that

By the way can someone please explain all of the other answers because well they make absolutely no sense to me. I can't even see how they refer to the question.

Answer 3

1+2 can = 4 if there was no such thing as zero. That way you would start at 1 and then add 1 and add 2 to equal 4.

Or you can use a different system of numerals where 3 is removed so if you were counting it would go 0,1,2,4 and 4 replaces the 3.

Answer 4

Go back through the questions / answers here: this question comes up every other day!
(multiply both sides by something, manipulate equations, somewhere divide by a subtraction of which the result is zero. You do not "prove" 1+2=4, you just make a wilful mistake).

Answer 5

You would know it that I love math, can't you see my ID?

Too prove that 1+2=4, try to use trigonometry. Because my answer for 1+2=3. Hehehe!

Answer 6

Please refer to the example below and you will realize the answer...

x+y=2
2x+2y=5

when you solve system of equations you will get

0= -1

but this does not mean that 0= -1

the contadiction 0= -1 this simply means that the system has no solution...

By the way,THe system does not have any solution because if you get the slope of both equations, you'll find out that the have the same slope (m= -1)
This means that there graphs are parallel lines. Parallel lines never meet. Hence, there is no solution because the solution should be the intersection of both lines...

Answer 7

1+2 = 4
3 = 4

if you multiply the left side by smthng, you also have to multiply the right side by the same thing rite? so:

3*0 = 4*0
0 = 0

Hence, this shows that boths sides of the equation are equal!

Answer 8

Have you make any mistake for this question?This possibility with
1+2=3 &
1+2p=4
But no the question like 1+2=4 leh
???

Answer 9

Its a common Roman Numeral trick ..

one is written as I and two as II in Roman numerals...
the three lines u've got can be rearranged as IV .. which is 4 ..
so 1+2=4
;)

Answer 10

your teacher has done some misatke cause my dear 1+2 = 3 only it can not be 4.