2.0x10^-5 or 2.0E-5 —this is because as a small decimal number, you move the decimal to the right five spaces and then add a negative to the decimal to indicate that when you translate back (from scientific notation to 0.00002) you will move the decimal to the left
These are called integer numbers.
We start with natural numbers (or whole numbers), i.e. the set

When you add the opposite of each whole number, you have the set of integers:

Answer:
Mr. Levy will pay 40% of the price, which is $2.80.
Step-by-step explanation:
Hope this helps!