so you are looking for the slope!! slope equations are always rise over run!! in this you have a negative line because it is going down. you had to rise one to get to the other point and move three points! this would get you -1/3!
This question requires you to know the lowest common multiple (LCM) of 5, 4 and 2. there are a few ways to do that. in this case the LCM would be 20. this means that in 20 year the science department would buy all 3 equipment at the same time
