The answer is incorrect because 12 should be negative not positive.
Step-by-step explanation:
1. 19 + -31 = - 12
2. Twelve is negative because if you were to start off at -31 and add 19 the answer would remain negative since -31 in a sense is "bigger" than 19. You would need more of a positive number to make -31 positive such as 40.
4*25= 100. There are 26 tables. At each of the 25 tables 4 people are sitting. Which means 100 people are sitting in complete tables of 4 people. That means that at the 26th table 3 people are sitting. 103-100= 3. Hope that helps. :)
