Well first you find the common denominatior of 1/7 and 4/9 which is 63 so then you see how many times does 7 go into 63 so this is part where you multiply 7 and 9 which gives you 63 and then you do how many times 9 go into 63 which is 7 so then you will take 7 times the 4 which is 28 so now your fractions should be 9/63 and 28/63 then now your next step is to add the 9 and 28 which is now 37/63 and you ask yourself and you divide that by any number to get a smaller number which is no so that is your answer