## anonymous 5 years ago I am doing Simplifying rational expressions its adding a fraction. I will attach the probem so you can see it clearer (:

1. anonymous

Here it is :

2. Yuki

hey dolly, still having trouble with rationals ?

3. anonymous

ya >.<

4. Yuki

can't open it

5. anonymous

can u see the attachments all i see is links :P

6. anonymous

Hmmmm ok then hold on (:

7. anonymous

x^2 - 16 / 4x + (x - 4)

8. anonymous

and the options are : x + 4 / 4x x + 1/ x x - 4 / x

9. Yuki

is it${x^2 - 16 \over 4x} + (x-4)$

10. anonymous

Yep!! (:

11. Yuki

the lowest common denominator is 4x, so you just find the equivalent form of x-4$4x(x-4) \over 4x$

12. Yuki

so when you simplify it, ${x^2+4x^2 -16x -16 \over 4x } ={ 5x^2-16x -16 \over 4x}$

13. anonymous

Ohh so you factor the numerator and then they cancel out? >.< i think i might be confused ^^

14. Yuki

I don't think the problem is right. because the rational form only goes this much and even if you do long division you still don't get any answer from the choices you gave

15. anonymous

Ya thats why i was stumped >.< but those are the exact answers they gave me

16. anonymous

what do u think i should do? (:

17. anonymous

Hmmm alright my teacher says to divide so will you help me with dividing them? (:

18. Yuki

I am thinking that the problem is actually ${x^2-16 \over 4x(x-4)}$

19. anonymous

No it isnt i wish it was >.< my teacher said it was a typo and ur suppossed to divide... :P go figure lol

20. anonymous

will u still help? (:

21. Yuki

hmm, this one would be (x+4)/4x = 1/4 +1/x

22. Yuki

okay, then let's just do long division

23. Yuki

$(x^2-16 \over 4x$

24. Yuki

can be written as follows ${x \over 4} - {4 \over x}$ by long division

25. anonymous

Wait so then it would have to be A or C right?

26. Yuki

when you add x-4 you will get ${x \over 4} - {4 \over x} +x-4$

27. Yuki

you can't go further if you make it into one big fraction, it's the one with the 5x^2

28. anonymous

Hmmm thats so strange!! why are all my problems like that!:P

29. Yuki

even if you work from the answers none of them match for example x + 4/x = $x^2 +4 \over x$ so it's not the answer

30. anonymous

>.< That is frackin frustrating :P lol i gave u a medal tho cuz at least u tried (:

31. anonymous

So then for the problem : 10a^2/7b^2 / 25a^3/14b^3 what would be the answer? (:

32. Yuki

let's work one by one the rational expression can be written as such by making a division into a multiplication and taking the reciprocal ${10a^2 \over 7b^2}*{14b^3 \over 25 a^3}$

33. Yuki

now this is a lot easier, the a's b's can cancel and 10 and 25 have something in common etc..

34. anonymous

oh ya!!

35. Yuki

you will end up having $2b \over 5a$

36. Yuki

oops, make that 4b/5a

37. anonymous

ohhhh ya i just did that whole problem after u said u dont long divide im such a frickin blonde lol thanks!! i asked for help when i didnt even need it... figures :P lol

38. anonymous

Ok i am retaking an assignment and i will prolly be checking or asking for help on here do you think you can help? (: or will ay least be on .... ?(:

39. Yuki

unfortunately I need to go :( Good luck though. My advise is to take each step slowly 1), find LCD 2), make all rationals equivalent form with the LCD 3), add the numerators 4), once simplified, check if it factors 5), check if there is anything in common with the denominator also, keep the denominator factored, because it would be an extra step to expand it