Answer and step-by-step explanation:
a. An appropriate scale to graph a credit of $35 and a debit of $40 is an scale of five units, this because $35 and $40 are divisible by 5. So, when graphing in the straight line, you will have steps of five units from 0 until -35 and then from 0 until +40. Take a look to the first image.
b. A credit is a negative concept in a bank account, that means that a subtraction of money to the account has been made. So, the integer that represents a credit of $35 is: -35.
c. A debit is a positive concept in a bank account, that means and addition of money to the account has been made. So, the integer that represents a debit of $40 is: +40.
d. The second image describes the location of -35 and +40 integers in the straight line.
e. Zero represents that you do not have money in your bank account and also that you do not have debts or negative balance. That means, no debits and no credits in your bank account.