Final answer:
This high school level mathematics question involves solving an equation and understanding the universal rules of arithmetic to guarantee the accuracy of the solution.
Step-by-step explanation:
The question at hand revolves around the solving of an equation in mathematics. Equations are fundamental components of math that express relationships between variables and constants. In high school mathematics, students learn various methods to solve equations, confirming the validity of the solution through the universal rules of mathematics. When dealing with an equation, it's important to determine the unknowns, knowns, and form an equation that articulates the unknown in terms of the known. The student in the question appears to be solving an equation in one variable, which should yield a definitive answer once simplified and balanced.
For example, if we are given an equation like I1 = I2 + 13, and know that I2 is the result of some operation on a known value, we substitute and simplify to find the unknown I1. Following the correct mathematical procedures, the sum of 12 and 6 is not equal to 9, and therefore, if a student makes such a statement, it is incorrect per the universal rules of arithmetic.