I am not sure what you are trying to write here. If you have trouble aligning things, enclose the relevant portions between [code] and [/code] tags.
I would assume you meant , but that isn't an equation (this would just be simplifying an expression). Is there something missing to the right of that equal sign?
If it is just get a common denominator and join the fractions. The least common multiple of 4 and 8 is 8, so we do