1. Math Question, hard

There is a question that I can never figure out why it is wrong. Here is the question:

16-36=25-45
= -20
16-36+20.25=25-45+20.25

FOIL / Complete the square...
(4-(9/2))^2 = (5-(9/2))^2
Sqrt it.
4-(9/2) = 5-(9/2)
4=5

why is it wrong?
This question held me prisoner for 5 hours and I just lost my last bit of hand-eye coordination.
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Engineer223

2. well, I'll take a look at it, but I'm sure that the problem is with the sqrt.

you see, you can't do

a^2=b
a=sqrt(b)

that's not true, the solution is

a^2=b
a=(+/-)sqrt(b)

that's because 5^2=(-5)^2=25

but I'll give you the full answer in a while

Oskilian

3. the trick is that when you square it, it can remove the negative... when you square it you are supposed to take the negative on the four and the positive on the five, thus giving you the difference... [+-0.5]

4. yup, that's it

Oskilian

5. hasafraggin 3 minutes...

6. What are you studying? I mean what grade.

7. kindergarten.

j/k

8. LOL, but don't be rude

9. Haha, I got the a similar problem once...

y=root X (can't type the root sign)
is a function

y^2=X
(square both sides)
is not a function...

10. y^2=X is a function.

11. Another Question

What is the answer to (10˛ + 11˛ + 12˛ + 13˛ + 14˛) / 365 WITHOUT using your calculator.

Hint: {}
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Engineer223

Midterm on Friday!!! ahhhh!!! [banging my head on the wall]

12. simple...2 :-)
and no I didnt use a calculator.

y^2=X is a function.
no it isn´t, a function must have only one X value for each Y value, and this one doesn´t (for example: if X=4, y can be 2 or -2)

Oskilian

14. Ok here is one for you all.

y^x = x^y

x and y are not equal.

15. x=4
y=2
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