Math help (Algebra II)

johnjohn320

Diamond Member
Jan 9, 2001
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I keep coming up with the wrong answer, apparently.

Solve the Equation.

(10/x+3) + (10/3) = 6





It seems easy enough, but I keep coming up with the wrong answer for some reason.
 

fatbaby

Banned
May 7, 2001
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6 - 3 1/3 = 2 2/3

10/x+3 = 2 2/3

10 = 2 2/3x + 8

2 2/3x = 2

x = 3/4

edit: and i'm a dumba$$ and even i know it, you should be ashamed of yourself
 

MacBaine

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Aug 23, 2001
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Originally posted by: johnjohn320


(10/x+3) + (10/3) = 6

(10/x+3) + (10/3) - (10/3) = 6 - (10/3)

(10/x+3) = (6-(10/3))

(10/x+3) -3 = (6-(10/3)) -3

10/x = (6-(10/3)-3)

- Cross Multiply -

(10/(6-(10/3)-3)) = x

x = -30
 

johnjohn320

Diamond Member
Jan 9, 2001
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Originally posted by: fatbaby
6 - 3 1/3 = 2 2/3

10/x+3 = 2 2/3

10 = 2 2/3x + 8

2 2/3x = 2

x = 3/4

edit: and i'm a dumba$$ and even i know it, you should be ashamed of yourself


Doh! Ok, that was my mistake, I for some reason was trying to multiply each side by 10/3, rather than just subtracting it. Ok, thank you!
 

konichiwa

Lifer
Oct 9, 1999
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Originally posted by: MacBaine
Originally posted by: johnjohn320


(10/x+3) + (10/3) = 6

(10/x+3) + (10/3) - (10/3) = 6 - (10/3)

(10/x+3) = (6-(10/3))

(10/x+3) -3 = (6-(10/3)) -3

^ There's your error. It's (10)/(x+3), x+3 being the denominator. You can't just subtract 3.

10/x = (6-(10/3)-3)

- Cross Multiply -

(10/(6-(10/3)-3)) = x

x = -30

 

jlarsson

Golden Member
Jul 31, 2001
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Originally posted by: MacBaine
Originally posted by: johnjohn320


(10/x+3) + (10/3) = 6

(10/x+3) + (10/3) - (10/3) = 6 - (10/3)

(10/x+3) = (6-(10/3))

(10/x+3) -3 = (6-(10/3)) -3

10/x = (6-(10/3)-3)

- Cross Multiply -

(10/(6-(10/3)-3)) = x

x = -30

I was going to say, that's what I got in my head, and I just checked myself on paper. 3/4 isn't right.
 

johnjohn320

Diamond Member
Jan 9, 2001
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Yeah, all the -30 folks, I appreciate the help, but you are, unfortunately, wrong. :) I have the answer key right in front of me.
 

MacBaine

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Aug 23, 2001
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Originally posted by: johnjohn320
Yeah, all the -30 folks, I appreciate the help, but you are, unfortunately, wrong. :) I have the answer key right in front of me.

Well then you do it
 

agnitrate

Diamond Member
Jul 2, 2001
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Originally posted by: MacBaine
Originally posted by: johnjohn320


(10/x+3) + (10/3) = 6

(10/x+3) + (10/3) - (10/3) = 6 - (10/3)

(10/x+3) = (6-(10/3))

(10/x+3) -3 = (6-(10/3)) -3

Ah, misinterpreted. He meant 10 / (x+3), not 10/x + 3. He forgot the ( )'s but I just kinda assumed that's what he meant :)

-silver
 

MacBaine

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Aug 23, 2001
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WAaaaaaaiiit...... it is (10/x+3) or (10/(x+3))?

Edit: :p You need to be more clear with math like this.
 

BigJ

Lifer
Nov 18, 2001
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Originally posted by: MacBaine
WAaaaaaaiiit...... it is (10/x+3) or (10/(x+3))?

Thats why he had the brackets on the outside, or he coulda just written it 10/x + 3 instead of (10/x+3)
 

jlarsson

Golden Member
Jul 31, 2001
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Originally posted by: konichiwa
Originally posted by: MacBaine
Originally posted by: johnjohn320


(10/x+3) + (10/3) = 6

(10/x+3) + (10/3) - (10/3) = 6 - (10/3)

(10/x+3) = (6-(10/3))

(10/x+3) -3 = (6-(10/3)) -3

^ There's your error. It's (10)/(x+3), x+3 being the denominator. You can't just subtract 3.

10/x = (6-(10/3)-3)

- Cross Multiply -

(10/(6-(10/3)-3)) = x

x = -30



If this is the case, then he didn't correctly write the problem out. Order of operations???
 

johnjohn320

Diamond Member
Jan 9, 2001
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Originally posted by: jlarsson
Originally posted by: MacBaine
Originally posted by: johnjohn320


(10/x+3) + (10/3) = 6

(10/x+3) + (10/3) - (10/3) = 6 - (10/3)

(10/x+3) = (6-(10/3))

(10/x+3) -3 = (6-(10/3)) -3

10/x = (6-(10/3)-3)

- Cross Multiply -

(10/(6-(10/3)-3)) = x

x = -30

I was going to say, that's what I got in my head, and I just checked myself on paper. 3/4 isn't right.

Ugh...christ...Yes it is! plug and chug: (10 /(.75+3)) = 2 2/3, + 10/3 = 6
 

pray4mojo

Diamond Member
Mar 8, 2003
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how do you even get a negative answer for this? i got 3/4
just isolate the x on one side and multiply by x+3 to remove it as a denominator. should be pretty simple from there.

 

johnjohn320

Diamond Member
Jan 9, 2001
7,572
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Originally posted by: MacBaine
Originally posted by: johnjohn320
Yeah, all the -30 folks, I appreciate the help, but you are, unfortunately, wrong. :) I have the answer key right in front of me.

Well then you do it

Now now, don't get all defensive. I said i appreciate the help, I was just pointing out that the correct answer is 3/4 according to my textbook. Geez, dont be so touchy!
 

BigJ

Lifer
Nov 18, 2001
21,330
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Originally posted by: pray4mojo
how do you even get a negative answer for this? i got 3/4
just isolate the x on one side and multiply by x+3 to remove it as a denominator. should be pretty simple from there.

Screwed up on parens