Final answer:
To arrange the given numbers in decreasing order, we need to compare them. After comparing each number, we find that the list in decreasing order is -1(3)/(5), -1.8, -1.45.
Step-by-step explanation:
The given list of numbers is:
-1(3)/(5), -1.45, -1.8
In order to arrange these numbers in decreasing order, we need to compare them. Let's start by comparing -1(3)/(5) with -1.45. Since -1(3)/(5) is a fraction and -1.45 is a decimal, we can convert the fraction to a decimal by dividing -1 by 5, which is -0.2. Now we can compare -0.2 with -1.45. -0.2 is greater than -1.45, so -1(3)/(5) comes before -1.45 in the decreasing order.
Next, let's compare -1.45 with -1.8. -1.45 is smaller than -1.8, so -1.45 comes after -1.8 in the decreasing order.
Therefore, the list of numbers in decreasing order is: -1(3)/(5), -1.8, -1.45.