Question

Which error, if any, was made?
The substitution property of equality was not applied correctly.
The addition property of equality was not applied correctly.
The multiplication property of equality was not applied correctly.
No errors were made.

Answer 1

$2x-8=12\ \ \ \ |\cdot\dfrac{1}{2}\\\\\left(\dfrac{1}{2}\right)2x-\left(\dfrac{1}{2}\right)8=12\ \ \ |\text{here you have the mistake}\\\\\\\boxed{\text{The multiplication property of equality was not applied correctly.}}$

Answer 2

2x-8=12
First you add 8 to both sides...
2x = 20
Then you divide each side by 2...
x = 20
Done

Wrong things...
- did not do the same thing to the entire side of each side
- wrong multiplication choice