To multiply fractions together you times the top and bottom numbers together and simplify:
(12*5)/(25*18) = 60/450
Then to simply you find a common number, the largest number you can divide into 60 and 450 and still be left with a interger (whole number), in this case it is 30. Then you divide the top and bottom by it:
(60/30)/(450/30) = 2/15
Hope this helps! :)
