Answer:
The step 4 and 5 describe the errors Stephen made.
Explanation:
Given : Stephen evaluated 
. His work is shown below.
To find : Which two statements describe the errors Stephen made?
Solution : 
Step 1 - 

Step 2 - 

Step 3 - 

Step 4 - 

Error is the step as 4 sign is negative.
So correct step is 

Step 5 - 

Error is the step as there is 4 in place of 3.
So correct step is 

The step 4 and 5 describe the errors Stephen made.