A. Equilateral because it says” same measure”
First the question asks you how many problems Cesar did per day in a 5 day school week. We know that he did 100 problems in that 5 day week, so you should divide 100 by 5 to get 20. Now we know that Cesar does 20 problems per day. Now the question want you to find how many problems he would do if this rate keeps up in three 5 day weeks. We know that he does 100 problems in a five day week, so multiply 100 by 3 to get 300. So Cesar does 300 percent problems in three weeks and 20 problems in one day.
Now we add the two digital times 3×3000 we can buy four stars 10 my fours are worth 4×10 and T55 digitals no awesomely
Rewrite the term 
Expand each term so we have
Use the fact that 
Use the fact that 
when a is an even number
Simplify
Let me know if you need any clarifications, thanks!
