Let S be the amount in a savings account. Let m be the number of months.
General equation S = 132 + 27m
Specific question July is the 7th month of the year including both January and July. S = 132 + 7*27 S = 132 + 189 S = 321
Reasonableness? Good question. You could estimate an answer. Start with 150 dollars and say that you add 25 a month. 7 * 25 = 175 S = 150 + 175 = 325 All of this was done in my head. Since the exact answer obtained using the formula is 321, I think that's pretty reasonable using my estimate is a guide.
The reason why c = 6n + t is the same as c - t = 6n is because c is the sum of the addition problem. 6n and t are the addends. The inverse operation for addition is subtraction. c is the cost that will be reduced by t. The answer is still 6n.
Factors of 792: 1, 2, 3, 4, 6, 8, 9, 11, 12, 18, 22, 24, 33, 36, 44, 66, 72, 88, 99, 132, 198, 264, 396, 792. Factor pairs: 792 = 1 x 792, 2 x 396, 3 x 264, 4 x 198, 6 x 132, 8 x 99, 9 x 88, 11 x 72, 12 x 66, 18 x 44, 22 x 36 or 24 x 33.