Algebra Word Problems and Hindu-Arabic, Mayan, Roman numbers

Please see number 1 and the following problems on the attached file :

3-2
6. Wally kept track of last week's money transactions. His
salary was $150 plus $54 in overtime and $260 in tips. His
transportation expenses were $22, his food expenses were
$60, his laundry costs were $15, his entertainment expenditures
were $58, and his rent was $185. After expenses,
did he have any money left? If so, how much?

3-3
13. On a 14-day vacation, Glenn increased his caloric intake
by 1500 calories per day. He also worked out more than
usual by swimming 2 hr a day. Swimming burns 666 calories
per hour, and a net gain of 3500 calories adds 1 lb of
weight. Did Glenn gain at least 1 lb during his vacation?

Ch 4

4-1
17. For which integers a, b, c does a - b - c = a- (b - c)?
Justify your answer.

4-2
42. Hosni gave the following argument that _ _ _
(a + b) = a + b
for all integers a and b. If the argument is
correct, supply the missing reasons. If it is incorrect,
explain why not.
-( a + b) = ( -1) ( a+ b)
= (-1) a + (-1)b
= -a + -b
4-3
2.
b. A forester has 43,682 seedlings to be planted. Can these
be planted in an equal number of rows with 11 seedlings
in each row?

26. Using only divisibility tests, explain whether 6,868,395 is
divisible by 15.

4-4

31. Explain why the product of any three consecutive integers
is divisible by 6.

Classroom questions:

A fourth-grade student devised the following subtraction
algorithm for subtracting 84 - 27.
4 minus 7 equals negative 3.

84
-27
-3
80 minus twenty equals 60.
84
-27
-3
60
60 plus negative 3 equals 57.
84
-27
-3
+ 60
57

Thus the answer is 57. What is your response as a teacher?

18. A student claims that every prime greater than 3 is a term
in the arithmetic sequence whose nth term is 6n+ 1 or in
the arithmetic sequence whose nth term is 6n - 1. Is this
true? If so why?