Answer:
Step-by-step explanation:
if Meredith bought 20 kg and Courtney bough 10 kg less you'd do 20-10 to find how much Courtney bought, hopefully that makes sense. We are going to do the same thing here.
That means 2/5 - 1/10. To subtract fractions you need common denominators, like 5/6 - 1/6 = 4/6. The bottom numbers need to be the same. So how do we do that? Well, that 4/6 can be rewritten as 2/3, they are the same number. So we want to do the same with either 2/5 or 1/10... or maybe both. Well 4/6 becomes 2/3 because 4/2 = 2 and 6/2 = 3, so we need to use that thinking.
in 2/5 - 1/10, do you see something we can multiply by to make the bottom numbers the same? What if you multiplied 2/5 by 3 on the top and bottom? that would get us 6/15. Well that's too high, maybe we try 2 then. 4/10. And hey, that got us a 10, so we idn't have to change 1/10. Now we can do the problem.
2/5 - 1/10 = 4/10 - 1/10 = 3/10.
So Courtney bought 3/10 kg
To find the total weight we add. So now we have a similar problem.
2/5 + 3/10 Well we know what to change 2/5 to to get a 10 at the bottom.
2/5 + 3/10 = 4/10 + 3/10 = 7/10.
So in total they bought 7/10 (seven tenths) of a kilogram.
Let em know if something didn't make sense.
