Final answer:
Holly used the property of isolating the variable and the solution is a = 17.92.
Step-by-step explanation:
To solve the equation a - 4.1 = 13.82 for a, Holly used the property of isolating the variable. The solution would involve adding 4.1 to both sides of the equation to isolate a. It would look like this:
a - 4.1 + 4.1 = 13.82 + 4.1
This simplifies to:
a = 17.92