(Please help me) Arlene is showing her work in simplifying −7.9 + 8.2 − 3.4 + 2.1. Identify any errors in her work or in her reasoning. Write feedback to Arlene explaining the mistake she made and how to correct her work.

To solve this problem you must apply the proccedure shown below:

1. Arlene only had to group the numbers with equal sign, as following:

2. And then, she must sum the numbers with equal sign:

3. Now, she must find the difference between these two number and assign the sign of the bigger number to the result:

A(t)= 18000(0.988)^t

Step-by-step explanation:

Given data

Ryan bought a brand new car for $18,000

Its value depreciated at a rate of 1.2%

Let us use the compound expression

A= P(1-r)^t

substitute

A= 18000(1-0.012)^t

A(t)= 18000(0.988)^t

Hence the expression is A(t)= 18000(0.988)^t