Word problems are the best to model real world problems. Most word problems use real world situations and problems that need a solution that can be solved through operations
You lost $100 because 300-200 is 100.
Call x as the number of months that Marc and Corinna have the same number of book.
45 +4x= 61 +2x
4x- 2x= 61-45
2x= 16
x= 8
13421= 10000+3421 (sumã de două nr. naturale)
13421= 23000-9579 (diferența de 2 nr. naturale)
