To simplify
First of all, Octavia error can be spotted from the correct steps below
Step1: Expand the expression
Step2: Collect like terms
Step 3: Simplify by using exponents laws
Step 4: Combine the terms.
The value is
Her error was that she didn't apply the exponents' law properly.
One of the laws she violated was
Her mistake was that she did
So she missed it from our step 1 above