One of the fundamental topics taught in the microeconomics class is minimizing economic costs. It includes understanding the concept of derivatives and applying them. However, most of the first-year undergraduate students find calculus difficult to understand, which also results in poor knowledge of optimization. We use the method based on the weighted inequality between the arithmetic mean and the geometric mean to explore if such a non-calculus approach can help students solve selected problems and understand the underlying concepts. The method is transparent and intuitive and requires only algebraic manipulations. Although this approach is generally not superior to calculus, it is a good introductory method that can help students understand and adopt more complex terms and procedures required by calculus.