Abstract-In this article, the mathematical model of the state support of investments is analyzed. The target function represents the maximal tax budgetary payments; the system of restrictions consists of linear and nonlinear functions, which corresponds to normative data. The maximal tax efficiency portfolio is generated by the principle of Pareto. The relevance of the proposed model follows from the current development of Russia and the situation on the international financial markets. In this regard, mechanisms and models are needed to assess the effectiveness of the funds invested by the state. The author proposes and analyzes a mathematical model of state support for investments. The target functional is the maximum tax budget allocations, the system of restrictions -linear and nonlinear functions, corresponding to regulatory data. It is proved that the formulated problem is a convex programming problem. According to the Pareto principle, an optimal set of basic criteria characterizing the financial stability of the investment project is determined. The portfolio is formed by the criterion of maximum tax efficiency. To solve the problems of assessing the effectiveness of investment projects today, there is a wide range of instrumental methods. Thus, using the mathematical model of state support for investments, the state obtains a mechanism to increase the efficiency of its activities, to support the modernization and technical re-equipment of enterprises in the most painless ways without losing its independence, and also to predict the consequences of its actions on the monetary policy being implemented.

Abstract-To ensure long-term financial stability and enterprise sustainability, executives need a strategic approach in solving financial problems, in effective ways of investing and in creating models for investment analysis and forecasting. The offered mathematical model allows one to provide optimization of decisions in strategic management of investments. The technique of using several sources of financing as part of an investment portfolio is described. Various combinations of sources of financing for different terms of crediting are considered. There are different methods of making decisions on investment projects, based on the analysis of various criteria, which fall into two broad categories: conventional (not discounting) and discounting. The main function of the funds invested in the project is the generation of such cash flows which allow predicting the investment attractiveness of the project and efficiency. The author is interested in the dynamics of the cash flow generation process, which is ensured by the use of discounting. Investment projects have different qualitative and quantitative characteristics: financial, technological, organizational, temporary, etc. All of them are important, but financial assessments of investment policy are crucial in many cases. The author examines the criteria that are crucial for characterizing the investment process. The use of economic and mathematical models makes it possible to take into account various requirements, conditions, and to obtain variants of investment project scenarios. These criteria characterize the project's own effectiveness in generating cash flows, which is large compared to other weight criteria in proving project feasibility.