Answer:
See if this will help,
https://www.pmschools.org/site/handlers/filedownload.ashx?moduleinstanceid=701&dataid=3612&FileName=2015%20triangle%20proofs%20answers.pdf
Let's look at it like this:
5/10+1/5 = (5/10) + (1/5)
5/10 = 0,5
1/5 = 0,2
so it's 5/10 + 1/5 = (5/10) + (1/5) = 0,5 + 0,2 = <u>0,7 </u>
[2*(10 + 5)] - 5
[2*(15)] - 5
[2(15)] - 5
[30] - 5
25
12 and 1/8 because you change 5 1/4 into 5 and 2/8. Then you add them togther and get 12 1/8