Doctor misses his girlfriend, Derpy, who likes number ⑨ a lot because of a certain ice fairy who is often compared with Derpy, he knows she likes this number, so… .
 
And look at Lyra, she might have been to human world and meet math geeks who don’t know how to use math properly and useful, being obsessed human fan, she went on and do it anyway.

is tbe answer 10?  
I did mental math but my mental math is terrible, plus i need a refresher on THAT kind of math too soooo…

@Background Pony #2F81  
score is 10, checked in on a graphing calculator

Score is -25 I believe. You subtract the 2x from the X, square the square root and the 7. Next you add 1 to 49 (7 squared) to get fifty and add the -x with the other-x to get -2x then do 50/-2 and you get X=-25, unless I completely fucked up somewheres

Soooo… what is her actual score? X=10 but it’s part of the equation. It comes out to 13=13. It’s supposed to go from 0-10.
 
Well, the max combined score is 30, so I guess it can still work as that would equal out to 29 from all 3 judges.

@Background Pony #F668  
You have the correct answer, but you have not been reading the entire thread.

@Background Pony #29DF
 
@Red Rover
 
@when she felt her wings unfold
 
@Vanchees
 
@Background Pony #F796
 
All these answers are wrong, X is 10.
 
(10) + sqrt (10-1) =2(10)-7  
(10) + sqrt (9)=20-7  
(10) + 3=13  
13=13

Dear Al gebra,
 
No, I don’t know who your ex is, or why she left you. So, please stop asking
 
Insincerely,  
Dragoj00

The answer is 3.
 
x+sqrt(x-1)=2x-7 [-x]  
sqrt(x-1)=x-7 [+1]  
sqrt(x)=x-6
 
If x=9
 
Or something like that.

X+sqr(x-1)=2x-7  
sqr(x-1)=x-7  
x-1=(x-7)^{2  
x-1=(x-7)(x-7)  
x-1 = x}2 - 14x + 49  
x^2 - 15x + 50 = 0
 
Link so I don’t have to explain the quadratic forumla  
link  
a=1 b=-15 C=50
 
Bippity boppity boop
 
x=10 or x=5
 
I got an A in Pre-calculus, so there.

Might I add, a score of 2 might also be the reason for the smug look on her face.

2 (I think)
 
Stage one: square both sides
 
x^{2 + x-1 = 2x - 7
 
Stage two: Get all the x’s on one side, and numbers on the other:  
x}2 - x = -6
 
Stage three: Quadratic formula results in 2. We don’t use the negative answer because the number for Lyra’s score must be positive (from 0-10).

For the last fucking time, NOBODY SAID THERE’D BE MATH!

so X=10  
and the actual equation equals 13

This is it. This is why I’m in college.

WARNING: equations below (not that you mind)

@kisk76  
No country is perfect, sadly.

@Techy Pony
 
@Background Pony #0CB8
 
Yeah, I agree it’s not a good choice to immigrate to Korea.
 
 
While Korea has a bright side, this country also possesses lots of tragic side.  
Korea is also notorious for “night study”, which is extremely, stressful to students.

@Background Pony #0CB8  
I did have a reason for saying “I don’t really want to move to South Korea”
 
@Ilsor  
Whether that’s the case or not, it results in the same answers so it’s just a matter of convention.

@Vanchees  
Longer form. You squared each piece of the sums and subtractions on both sides of the = sign independently. That’s not going to retain the condition expressed by the equation, which is sort of the key idea in algebra. Simple numeric demonstration
 
1 + 2 = 3
 
nice and easy, and true! But you can’t transform it by doing
 
1² + 2² = 3²  
1 + 4 = 9
 
because that generates a falsehood as above. To retain the equation’s condition, you’d need to instead do
 
(1 + 2)² = 3² ; binomial expansion, (x+y)² = x² + 2xy + y²  
1² + 212 + 2² = 9  
1 + 4 + 4 = 9  
9 = 9
 
so the condition has been maintained.

@Vanchees  
Right in the beginning.
 
When you raise “a + b” to the second power, the result is not “a^{2 + b}2”, the result is “(a + b)^{2”, which is “a}2 + b^2 + 2ab”.

Raise both sides of the equation in a square,we’ve got: x^2+x-1=4x2-49  
then transform this in quadratic equation:  
3x^2-x-48=0  
find the discriminant:  
D=1-43(-48)=577.Ok,this is irrational root,about it 24 (in fact,root from D is 24,020824)  
And now let’s find x. x=1+24/2*3=4 (it,s not exact result,real result is 4,166666666).  
Where I made a mistake ?

I’m gonna try to make it as simple as I can.

The √ of something is always a positive number.

x^2 = 4 has, indeed, two roots, but they’re not “-2” and “2” as much as they’re “-√4” and “+√4”.

“x = 5” would be the solution for the same equation, but “x+√(x-1)” being replaced with “x-√(x-1)”.

@kisk76
 
@Techy Pony
 
But South Koreans can get very cruel when it comes to bullying. If you are smart or strong, you are safe, but if you are a shy whimp, the entire class will bully you. They will force you to run errands for them, buying stuff from the shop for them. And most of the times, they will force you to pay for the stuff, so it’s pretty much a daylight robbery. Some will force you to pay for 3G internet fee or buy cigarette packets for them. You will even be called by the name, ‘bread shuttle’(빵셔틀).
 
Currently, South Korea has highest teenagers suicide rate world wide. Guess why.

x=2