Final answer:
The expression that has a value of 7 on top of 12 is 7 + 12.
Step-by-step explanation:
The expression that has a value of 7 on top of 12 is b. 7 + 12.
To evaluate this expression, simply add 7 and 12 together. The sum of 7 and 12 is 19, which is the value of the expression.
So, the correct answer is option b.