subtracting rational expressions

[smokin92]

I know how to add and subtract these when they have common denominators, i just have no idea how to get them there.

So if you can explain to me how you would get the common denominator, i can do the rest.

Thank you


3 8
-- - ----
x-3 x
( sorry i cant get the problem to look right, it should be:
3 over x minus 3 minus 8 over x

 

[Guest]

Your LCD for this problem would be (x)(x-3)

So you'll have (3x)/(x)(x-3) minus (8x-24)/ (x)(x-3)

Hope this helps, my son has been working on them and is finally understanding them!