Answer: The value of x will be 2.
Explanation:
To calculate the value of 'x' or solve for x, we need to isolate x from 8.
In the equation, 8 is in addition with 'x' so for isolating it, we need to apply the reverse operation of addition.
Reverse operation of addition is subtraction.
We need to subtract 8 from both sides of the equation, we get:

By doing this, we get the value of 'x' as 2.
Error done by Alice was that she added 8 and it did not led to the isolation of 'x'.