Answer:
No, the student's work is not correct.
Step-by-step explanation:
Given : Student expanded an expression, as shown.



To find : Is the student's work correct?
Solution :
The expansion of student is not correct.
Follow the below steps to get correct solution and student mistake,
Step 1 - Write the expression,

Step 2 - Apply distributive property, 

Step 3 - Solve,

The student was mistaken in step 2 in solving the sign.