Amy had homework for math science and history she spent 1/3 of her time working on math and 1/4 of her time working on science how much time did she use to do history

The answer would be 5/12 because you have to get like denominators, 4 and 3 both go into 12, and then whatever you do to the bottom you must do to the top, so for 1/4 you did 4 times 3 = 12 so you do 1 times 3 = 3 so 3/12, and for 1/3 you do 3 times 4 = 12 so you do 1  times 4 = 4 so 4/12. Then you add 3/12 and 4/12 together to equal 7/12 then 12/12 minus 7/12 = 5/12 -- sorry if that's too confusing