What's not to understand?
3 / (4+(1/2))
Alternatively, you might want to convert that 1/2 to a decimal and then do long division:
Hopefully this will stay formatted properly. Just in case, the 6 should be over the second 0.
_0.06________
4.5. | 3.0000
Remember to get rid of the decimal on the 4.5 and what you do to one, you do to the otherl:
_0.6________
45. | 30.000
You will have to do the rest of the work.