1/2 is not equivalent to 2/5 because there is a pattern. 1/2 equals to 2/4 and 3/6 and 4/8 and it keeps going on. 2/5 is not equivalent to 1/2 because look at 3/6 3 times 2 equals 6. Now look at 2/5 2 times 2 equals 4 so thats why they are not equivalent
