I’m not 100% sure but I think it’s a padlock that represents it
A macro is a series of commands and instructions that you group together as a single command to accomplish a task automatically.
Answer:

Explanation:
Given

Required
The result when
and
Analyzing the given instruction
a*=(++a)/(6)+(b++3)
Single out and solve the expressions in bracket
(++a) = a -- When the ++ operator appears before an operand, it is called pre increment. meaning that the operation will be done before the operand will be incremented.
So: in this case: ++a = a

The operator, as used in that statement is the same as: b + 3.
So:





The above expression is calculated as:

So:

