very lost

[rgeer]

If anyone could plese help me that would be great.

In problems 1-4 Find, in each case, the value of the variable for which the fraction is undefined. Show all work. :

1) x/x+8 would it be: x=x+8?. Im not sure how to do these but I know its something like that.
2)7/2-x
3)10/2x-1
4)1/x^2-4

In problems 6-9:Reduce each fraction to lowest terms. Show all work and steps. :

5)2x^-250/x^2+8x+15 do you cancel out one x?
6)r^2-4r-5/r^2-2r-15
7)48+8x-x^2/x^2+x-12
8)2x^2-7x+3/(x-3)^2
9)x^2-7xy+12^2/x^2+xy-20y^2

I think I know partialy what I'm doing, but im not sure fully.
Thank you very much in advance,
Ryan

 

[tkhunny]

You are going to have to get just a little better at notation.

x/x+8 MEANS (x/x)+8 = 1+8 = 9 -- Check your "Order of Operations" and see that this is so.

If you mean x/(x+8) you must use the parentheses.

x = x+8 does NOT define a value for x. Try x+8 = 0 and solve for x.

 

[stapel]

1) x/x+8 would it be: x=x+8?. Im not sure how to do these but I know its something like that.
2)7/2-x
3)10/2x-1
4)1/x^2-4

Your formatting is ambiguous.

1) You have posted (x/x) + 8 = 1 + 8 = 9. Do you mean "x/(x + 8)"?

2) You have posted (7/2) - x. Do you mean "7/(2 - x)"?

3) You have posted (10/(2x)) - 1 = 5/x - 1. Do you mean "(10/2)x - 1" or "10/(2x - 1)" or something else?

4) You have posted (1/x²) - 4. Do you mean "1/(x² - 4) = 1/[(x - 2)(x + 2)]"?

Whatever your meaning, they are asking you for the x-values, if any, that make these expressions undefined. Hint: Can you divide by zero?

Reduce each fraction to lowest terms.
5)2x^-250/x^2+8x+15 do you cancel out one x?
6)r^2-4r-5/r^2-2r-15
7)48+8x-x^2/x^2+x-12
8)2x^2-7x+3/(x-3)^2
9)x^2-7xy+12^2/x^2+xy-20y^2

I'm sorry, but there are just way too many interpretations for the above. Please reply with grouping symbols to clarify your meaning.

In general, to "reduce" a fraction, one cancels common factors. So when you reply, please include the factoring and cancelling that you have done.

Thank you.

Eliz.

 

[rgeer]

[quote="rgeer"
]1) x/x+8
2)7/2-x
3)10/2x-1
4)1/x^2-4

Your formatting is ambiguous.

1) You have posted (x/x) + 8 = 1 + 8 = 9. Do you mean "x/(x + 8)"? On the questions it says x divided by x+8.

2) You have posted (7/2) - x. Do you mean "7/(2 - x)"? yes, again like number 1 in that format but no parenthesis.

3) You have posted (10/(2x)) - 1 Do you mean "(10/2)x - 1" or "10/(2x - 1)" or something else? I mean 10 divided by 2x-1.

4) You have posted (1/x²) - 4. Do you mean "1/(x² - 4) = 1/[(x - 2)(x + 2)]"? I mean 1 divided by x^2-4.

In those problems there are no parenthesis.

Whatever your meaning, they are asking you for the x-values, if any, that make these expressions undefined. Hint: Can you divide by zero?

Reduce each fraction to lowest terms.
5)2x^-250/x^2+8x+15
6)r^2-4r-5/r^2-2r-15
7)48+8x-x^2/x^2+x-12
8)2x^2-7x+3/(x-3)^2
9)x^2-7xy+12^2/x^2+xy-20y^2

I'm sorry, but there are just way too many interpretations for the above. Please reply with grouping symbols to clarify your meaning.
For problems 5-9 I am completly clueless, I have no idea how to factor, that is probably my main problem.

In general, to "reduce" a fraction, one cancels common factors. So when you reply, please include the factoring and cancelling that you have done.

Thank you.

Eliz.[/quote]

 

[rgeer]

Eliz in response,

1) x/x+8
2)7/2-x
3)10/2x-1
4)1/x^2-4 [/quote]


1) the question it says x divided by x+8.

2) yes, again like number 1 in that format but no parenthesis.

3) I mean 10 divided by 2x-1.

4) I mean 1 divided by x^2-4.

In those problems there are no parenthesis.



Reduce each fraction to lowest terms.
5)2x^-250/x^2+8x+15
6)r^2-4r-5/r^2-2r-15
7)48+8x-x^2/x^2+x-12
8)2x^2-7x+3/(x-3)^2
9)x^2-7xy+12^2/x^2+xy-20y^2
For problems 5-9 I am completly clueless, I have no idea how to factor, that is probably my main problem.

 

[Gene]

Instead of explaining them you should learn "order of operations" or PEDMAS and type them so they say what you mean. If you ever get a calculator you can talk to it all day but it won't give the correct answer till you obey the rules.
If you refuse to learn them you can click twice on the Code button then type between the boxes like

      x
1)   --- + 8
      x
or
       x
     ------
      x+8

5 thru 9 are still ambiguous. You need ()s or Code.

 

[rgeer]

Ok,

for number 1 I got x=-8
2)x=0
3)dont know how to solve do you solve for 2x-1=0? which gives you 2x=-1
4)is it x^2=-4

5) I got 2y-25 over (x-11)(x-1)
6)r+1 over r+3
7-9 Im still unsure what to do.

7)

48+8x-x^2

x^2+x-12[/code]... still not getting the code.

8) 2x^2-7x+3 over (x-3)(x-3)
9) x^2-7xy+12^2 over x^2+xy-20y^2

 

[Denis]

Look rgeer, be nice and quit making everybody lose their time!

If you can't format properly, ask someone who can SHOW you.

"3)dont know how to solve do you solve for 2x-1=0? which gives you 2x=-1 "
That should be 2x=1
If you can't solve something so simple, how do you expect to understand the
others; some are over 10 times as hard...
you need to talk to your teacher.