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official math problem thread
Posted: Tue Mar 25, 2008 10:16 pm
by Tom
||| A | B | C ||| = (a + b + c)^(1/2)
||| 2x | 3x |4x ||| = 5x
x = ?
Posted: Tue Mar 25, 2008 10:30 pm
by Yuryeong
Code: Select all
2x + 3x + 4x = 5x
9x = 5x
x = 9/5
x = 1,8
Posted: Tue Mar 25, 2008 10:33 pm
by Tom
your first line should read:
Posted: Tue Mar 25, 2008 10:36 pm
by Yuryeong
(2x+3x+4x)^(1/2) = 5x
(9x)^0,5 = 5x
4,5 = 5x
x = 5/4,5
x = 1,111...
Posted: Tue Mar 25, 2008 11:16 pm
by JKL;!!!!!
i don't get this...
i'm onlyy grade 5 =(
Posted: Tue Mar 25, 2008 11:24 pm
by Yuryeong
Really?
Well is not too hard...
Let's explain with the basic...
"+" Is diferent of "-"
"."(Multiply) Is diferent of "/"
= Equal(Doh)
1 + x = 2
If I pass 1 to the other side of the "=" I turn this 1 to the diferent simbol(Or better, +1, when pass to the other side will be -1)
x = -1 + 2
or
x = 2 - 1
x = 1
2x, 3x(Is always 2.x or 3.x, you always multipy the X)
If it is:
1x(1x is the same as only x) + 1 + x = 2
2x + 1 = 2
2x = 2 - 1
2x = 1
(Pass the 2 of the X, 'cause X is ".", you pass in "/")
x = 1/2
x = 0,5
0,5 + 1 + 0,5 = 2
I SUCK AS A TEACHER!
Posted: Tue Mar 25, 2008 11:38 pm
by JKL;!!!!!
i see...
isn't that pre-algebra?
Posted: Tue Mar 25, 2008 11:41 pm
by Yuryeong
I think... Dunno... XD
I know how to do but i don't know the name of the things ;p
Posted: Tue Mar 25, 2008 11:44 pm
by JKL;!!!!!
---------------------------_
did you know that 0.99 = 1?
because 0.33 = 1/3, so, 0.99 = 1!
Posted: Tue Mar 25, 2008 11:45 pm
by Yuryeong
Cool... You smart
Do you know that in binary:
1+=10
10+1 = 11
11 + 1 = 100
Posted: Wed Mar 26, 2008 12:37 am
by Tom
correct answer: .36 or 9/25
proof:
Code: Select all
(2x + 3x + 4x)^(1/2) = 5x
√(9x) = 5x
9x = 25x^2
9 = 25x
x = .36 or 9/25
new problem:
Posted: Wed Mar 26, 2008 1:01 am
by Doctor What
I'm gonna give this a shot.
7sin(40) = 5sin(X)
awww crap, I can't find my ti-84...
Posted: Wed Mar 26, 2008 1:04 pm
by hobobuster
hahah mine is at home too
Posted: Wed Mar 26, 2008 2:57 pm
by CX gamer
7sin(40) = 5sin(X)
<=> sin(X) = 0.8999026535611550585170077387017
<=> X = asin(0.8999026535611550585170077387017)
<=> X = 64.14527° + k*360 (k ∈Z)
or X = 115.85473° + k*360 (k ∈Z)
Posted: Wed Mar 26, 2008 3:27 pm
by Peemore
JKL;!!!!! wrote:i don't get this...
i'm onlyy grade 5 =(
no way!
Posted: Wed Mar 26, 2008 3:47 pm
by atomtengeralattjaro
hey dont believe a word/number he says
Posted: Wed Mar 26, 2008 4:27 pm
by Tom
If 7x = 4y, and (y/z) = (7/5), then (x/z) = ?
Posted: Wed Mar 26, 2008 4:29 pm
by Peemore
(4/5)
Posted: Wed Mar 26, 2008 4:34 pm
by atomtengeralattjaro
yea..
7x=4y
y=(7/4)x
y/z=7/5
(7/4)x/z=7/5
35/20 x/z = 28/20
35x/z = 28
x/z=28/35=4/5
Posted: Wed Mar 26, 2008 4:41 pm
by Tom
excellent job.
okay, one more easy one before a harder one.
If the line containing the points (a,3) and (b,2) has a slope of 1/7, then a-b=?