i am having difficulty with this problem can someone help me.

Problem #1
Write in simplest form

(48a^5b)/(12ab^2)

this is what i get:

4a^4b^-1

Problem #2

how do i start it:

subtract. Express your result in simplest form

(12)/(z) minus (10)/(z)

Your #1 is correct, and can also be written 4a^4/b.

#2 12/z - 10/z = (12-10)*(1/z) = 2/z

canyou explain to me how do you determine to make it a 1/z

Z is a common denominator, so you can just add or subtract the numerators.

12/z - 10/z = (!2-10)/z = 2/z

The same thing is accomplished by extracting 1/z.

12/z - 10/z = (!2-10)(1/z) = 2/z

I hope this helps a little more. Thanks for asking.

thank you yes it does i appreciated...

if you wanted to find the definition of 6/25-four over five what common denominator should you choose?why?

You're welcome! I'm glad I could help clarify things for you. If you have any more questions or need further assistance, feel free to ask. Happy learning!