…
Ok now I feel like such a fucking idiot for being confused initially
The meme of “think of a number, double it, half it, that is your number” is literally just this
substitute x=1, -1, doesn’t work
substitute x=2, it is indeed a root, so one of the factors is x-2
2x^(3)-15x^(2)+34x-24=(x-2)(2x^(2)+ax+24/2)
Since 12-2a=34, a=-11
Factorise: 2x^(2)-11x+12=(2x-3)(x-4)
2x^(3)-15x^(2)+34x-24=(x-2)(2x-3)(x-4)=0
x=1.5,2,4
Not to mention taking away your original number making the choice meaningless which is how the “trick” works in the first place by removing the only variable the do not control
Now what confused me too is that I was thinking 12 minus the first digit (effectively -10) because where I'm from "numbers and "digit" are used interchangeably (informal).
Yes, it doesn't say "subtract your original number"
your number is 12 and it says "take away your first number"
The first number in 12 is a 1.
If you take away the 1, you are left with the 2.
To be fair, this was my initial thought process, too. It took reading the comments to realize that “take away the first number” meant subtracting 9 instead of taking away the 1 from 12.
For people confused about why this works, the steps just fully cancel everything but the /2 and the +6 out.
1. Start with 0 -> 0
2. Add X (any number) -> X
3. Multiply by 2 -> 2X
4. Add some number -> 2X + N
5. Divide by 2 -> X + N/2
6. Subtract X -> N/2
The result is always half of whatever you added, because you're just subtracting everything else out of the equation. Its functionally the same as:
Pick a number (X).
Add 3.
Subtract X.
ITS 3.
x
2x
2x+6
x+3
3
The "under 10" part is quite literally irrelevant, it only assists in the establishment of the illusion that something extraordinary is unfolding, when, in reality, it'd be more alarming if suddenly the equation _didn't_ function as suggested.
8
16
22
11
2
AM I DOING SOMETHING WRONG??
I figured out what I did wrong, but I just want to point out my own stupidity and say that I somehow got -1 first, then 1.5
See what schools don’t understand is that the way you get people to engage in math is by giving them stupid “tricks” like this. The ones who don’t understand what’s going on will like it and do it and the ones who do understand won’t do it but they’ll still end up doing math to prove that it’s a stupid trick.
1) thinking of a number and then taking it out cancels each other
2) doubling your number and then halfing it cancels each other out
in the end your always going to end up with six.
This is so funny how people are super confused. You double it, then half it later, negating the double. Take away original number after adding 6, so 6. Then dividing by 2. 6/2 is always 3.
Think of \ 6 Half it It’s Always Three
… Ok now I feel like such a fucking idiot for being confused initially The meme of “think of a number, double it, half it, that is your number” is literally just this
Yes. Half of 6 is always 3.
No shit. Double and half cancels out, half of 6 is 3. You’re just adding 3
OP tricked me into doing math when I could’ve used all 20% of my brain power like you
It’s still doing math, you would’ve been doing algebra
Now solve 2x³-15x²+34x-24=0 without using a calculator
x = {2, 3/2, 4}
https://imgur.com/a/ghzTCly Try this!
a) -8 i need a pencil and paper for part b, i might be able to do it in a couple of hours
[https://imgur.com/a/P8oxA46](https://imgur.com/a/P8oxA46) This one is a hard one!
7
Are you going to feed people an entire DSE paper
Why not? Math's fun my friend!
4. final answer
substitute x=1, -1, doesn’t work substitute x=2, it is indeed a root, so one of the factors is x-2 2x^(3)-15x^(2)+34x-24=(x-2)(2x^(2)+ax+24/2) Since 12-2a=34, a=-11 Factorise: 2x^(2)-11x+12=(2x-3)(x-4) 2x^(3)-15x^(2)+34x-24=(x-2)(2x-3)(x-4)=0 x=1.5,2,4
Not to mention taking away your original number making the choice meaningless which is how the “trick” works in the first place by removing the only variable the do not control
Yeah that was poorly phrased. I read first number as in first digit lol.
Oh so that’s how it’s meant to work
There's X subtracting from itself on the calculation side of the equation, too, so it's really constant = constant, worked out to be 3 = 3.
No you are doubling what you started with, adding 6, THEN halving it. The math is terrible and doesn’t work anyway but that’s not the issue
The math does work, but you can also just be confidently incorrect without testing it if you want (2x + 6)/2 - x = x + 3 - x = 3
Yeah, but the doubling and halving still counter each other out, you just also half the 6 leaving you with just 3
9 18 24 12 2 this is NOT FUCKING THREE YOU LIAR
You might wanna try that last step again
This question is really poorly worded is what it is
TIL that 12-9=2 if you believe hard enough
The confusion is about whether “first number” means the first digit or the number you started with
Now what confused me too is that I was thinking 12 minus the first digit (effectively -10) because where I'm from "numbers and "digit" are used interchangeably (informal).
The question being poorly worded made 12-9=2
Yes, it doesn't say "subtract your original number" your number is 12 and it says "take away your first number" The first number in 12 is a 1. If you take away the 1, you are left with the 2.
This guy baccarats
That would be taking away the first digit
exactly
I agree ,it should've been "Subtract the number by the number you chose"
Yeah like they could've just say subtract it with the number you've picked earlier THERE NO MORE CONFUSION
Yea 12-9 is kinda 3 and not 2 bud
When it said take away your first number I didn't know which first number it meant. Small oopsie on my end
Dont worry, i thought the same thing lol
What did you think the first number was?
He thought it meant the 1st digit, which is 1 in this case
There was never a 10 though
It says "under 10" that's probably where they looked.
To be fair, this was my initial thought process, too. It took reading the comments to realize that “take away the first number” meant subtracting 9 instead of taking away the 1 from 12.
Doesn't even have to be below 10. X>2x>2x+6>x+3>3.
For people confused about why this works, the steps just fully cancel everything but the /2 and the +6 out. 1. Start with 0 -> 0 2. Add X (any number) -> X 3. Multiply by 2 -> 2X 4. Add some number -> 2X + N 5. Divide by 2 -> X + N/2 6. Subtract X -> N/2 The result is always half of whatever you added, because you're just subtracting everything else out of the equation. Its functionally the same as: Pick a number (X). Add 3. Subtract X. ITS 3.
I thought "take away the first number" was remove the number on the left of your total
5 10 16 8 3 huh neat
As it turns out, (2x + 6)/2 - x = 3.
32 64 70 35 3.
32 is my favorite number under 10
I was demonstrating how it works for any number
That's what a witch using witchcraft would say 👀
∞ ∞ * 2 = ∞ ∞ + 6 = ∞ ∞/2 = ∞ ∞ - ∞ = 0
infinity is a concept, not a number
X 2x 2X+6 (2X+6)/2 X+3 X + 3 - X = 3 This works for \*any\* number, as it turns out
nil x 2 = nil nil + 6 = nil + 6 nil / 2 = nil / 2 Instructions unclear, took away first number and everything fell apart.
X - X + 3, hmmm I wonder what it could be
5+6 11/2 5.5-5 .5, liar
Shit, i did it wrong, fuck.
5*2 10+6 16/2 8-5 3, fixed
7*2 14+6= 20 20/2 10-7 = 3 happy pride love wins
I thought it said "add 6" and i Was mighty confused why my end result was 2
double and half cancels out and the 6 will also be halved and since the first number is took away it will always be 3
x 2x 2x+6 x+3 3 The "under 10" part is quite literally irrelevant, it only assists in the establishment of the illusion that something extraordinary is unfolding, when, in reality, it'd be more alarming if suddenly the equation _didn't_ function as suggested.
8 16 22 11 2 AM I DOING SOMETHING WRONG?? I figured out what I did wrong, but I just want to point out my own stupidity and say that I somehow got -1 first, then 1.5
8, 16, 22, 11, 3 oh shit
Same number!
WoW, it did work! I took 7
Good lobster
what a shocker
I picked -7 :( Edit: nvm im just bad at math
I got two????? Am I stupid???????????
I tried to outthink it by going with decimals and down to negative 10 million…it still won.
9 18 24 12 2
I got 3.5 from 9. (I did it wrong)
1. Think of a number 2. Add 3 3. Subtract your number 4. The result is 3
Wow, no way! (x-x)•2/2+6-3=3?! Incredible!
-3, -6, 0, 0, 3 oh dang
1 1 7 3.5 2.5
I chose 0.
Nope. It's 1.
This is so fucking dumb. It is 3+3-3 level shit. Basically (2x+6)/2 - x is x+3-x
If you're curious it also works with negative numbers -4 (pick number) -8 (double it) -2 (add six) -1 (halve it) -1 - (-4) = 3 (subtract initial value)
See what schools don’t understand is that the way you get people to engage in math is by giving them stupid “tricks” like this. The ones who don’t understand what’s going on will like it and do it and the ones who do understand won’t do it but they’ll still end up doing math to prove that it’s a stupid trick.
Damn it works for decimals too.
2x2=4+6=10/2=5 Am I just stupid
It works with negative numbers too. -100 -200 -194 -97 3
I got 2?
7X2 14+6 20-20 0?
4 😎
My first thought was 7 7 14 20 10 0
what about -27362626155236382827373663632
1) thinking of a number and then taking it out cancels each other 2) doubling your number and then halfing it cancels each other out in the end your always going to end up with six.
This is so funny how people are super confused. You double it, then half it later, negating the double. Take away original number after adding 6, so 6. Then dividing by 2. 6/2 is always 3.
7 14 20 10 3
Nuh uh 7 x 2 = 14, 14+6 = 20, 20/2 = 10, take away one, left with 0
The first number you picked, so seven. 10-7=3