3/4 - 4 z + 5/4 z - 1/2 + 1/2 z
First, put the like terms together:
-4z + 5/4z + 1/2z + 3/4 - 1/2
Find the LCM of the first three to turn them into one massive fraction:
-16/4z + 5/4z + 2/4z + 3/4 - 1/2
Do the same for the last 2 fractions:
-16/4z + 5/4z + 2/4z + 3/4 - 2/4
Simplify everything (keeping like terms in mind)
-9/4z + 1/4
And that's the answer :)
(I think)