can anybody help me?! I am really confused;)

1.) a-(5a/a+5) / a+(5a/a-5)

2.) (a/a-b) - (b/a+b) / (b/a-b) + (a/a+b)

3.) (a-b/a+b) + (b/a) / (a/b) - (a-b/a+b)

Thanks :D

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- Nov 13th 2006, 03:21 AMwhoaHelp!! Complex Fractions
can anybody help me?! I am really confused;)

1.) a-(5a/a+5) / a+(5a/a-5)

2.) (a/a-b) - (b/a+b) / (b/a-b) + (a/a+b)

3.) (a-b/a+b) + (b/a) / (a/b) - (a-b/a+b)

Thanks :D - Nov 13th 2006, 10:56 AMOReilly
- Nov 13th 2006, 01:02 PMwhoa
thanks! by the way how did you get the final answer?

- Nov 13th 2006, 01:07 PMSoroban
Hello, whoa!

The standard procedure for complex fractions is to multiply through by the LCD.

This allows us to cancel those annoying denominators.

Quote:

The LCD is

. .

Factor: .

Quote:

The LCD is

. .

. . .

Quote:

The LCD is

. .

. .

- Nov 14th 2006, 01:14 AMwhoa
Ah ok. thanks............ but I still have a problem. what if the numbers are raised by negative one? here are some examples:

1.) (3x^-1 - 2y^-1) / (2y^-1 - 3x^-1)

2.) {(3a)^-1 - (2b)^-1} / {(2b)^-1 + (3a)^-1}

3.) (ab^-1 + ba^-1) / {(ab)^-1}

:confused: - Nov 14th 2006, 02:49 AMOReilly
General rule when having number raised by negative number is:

I will show you examples from your equations for such numbers but you should try to do all this by yourself since you have been given help from Soroban and me for similar examples.

So we have

Notice that we only raised x by -1 not 3x.

You have also .

Notice that we raised 3a by -1 not just a.

Try to do something and this forum will help you in your effort. - Nov 14th 2006, 03:23 AMwhoa
uhm... i'm not sure here's my answer:

1.) (3/x -2/y)/(2/y-3/x) = {3(y)-2(x)/xy} = (3y-2x/xy)/(2x-3y/xy)= (3y-2x/xy) * (xy/2x-3y)=////////// (3y-2x)/(2x-3y)final answer

2.) (1/3a-1/2b)/(1/2b+1/3a) = {2b-3a/(3a)(2b)}/{(3a+2b/(2b)(3a)}={2b-3a/(3a)(2b)}*{3a+2b/(2b)(3a)}= ////////-3a/3a,,, final answer

3.) (1/ab+1/ba)/(1/ab)= (1/ab)/(1/ab)= (1/ab*ab/1)=///////////1,,, final answer

hehe i'm not sure;) - Nov 14th 2006, 03:56 AMOReilly
1) Correct.

2) Answer is not correct. You have done it almost ok but at the end you made an error.

Solution is:

can't be further simplifed as you did to

3) Not correct. You made a mistake at start.

It's not because only b is raised by -1. If it were then it would be .

Correct is .

Now, try to do 3) again. - Nov 14th 2006, 04:07 AMwhoa
wow! thanks

here's no. 3;) i'm not sure again hehe

(a/b+b/a) / (1/ab)= [a(b)+b(a)/ab] / 1/ab= (ab+ba/ab) / 1/ab= (ab+ba/ab)*ab/1=///////// (ab+ba/1),,,, final answer - Nov 14th 2006, 04:46 AMSoroban
Hello, whoa!

Why don't you try it my way? . . . Or don't you understand it?

Quote:

We have: . . . . . The LCD is

. .

Quote:

We have: . . . . . . The LCD is

. . . . . cannot be reduced

Quote:

We have: . . . . .The LCD is

. .

- Nov 14th 2006, 05:22 AMwhoa
thanks for lending your time to me you guys:) I'd really appreciate it! I learned a lot!

@ soroban

Quote:

. . . . . [/size]cannot be reduced

thanks - Nov 15th 2006, 02:04 AMwhoa
ok know it already! thanks anyways:)