Part I: Corporate Finance: Introduction -- Capital Structure: Modigliani–Miller Theory -- Modern Theory of Capital Cost and Capital Structure: Brusov-Filatova-Orekhova Theory (BFO Theory) -- Bankruptcy of the Famous Tradeoff Theory -- New Mechanism of Formation of the Company Optimal Capital Structure, Different from Suggested by Trade Off Theory -- The Global Causes of Global Financial Crisis -- The Role of Taxing and Leverage in Evaluation of Capital Cost and Capitalization of the Company -- A Qualitatively New Effect in Corporate Finance: Abnormal Dependence of Equity Cost of Company on Leverage -- Inflation in Brusov–Filatova–Orekhova Theory and in Its Perpetuity Limit – Modigliani – Miller Theory -- Part II: Investments: A Portfolio of Two Securities -- Investment Models with Debt Repayment at the End of the Project and Their Application -- Influence of Debt Financing on the Efficiency of Investment Projects: The Analysis of Efficiency of Investment Projects within the Perpetuity (Modigliani–Miller) Approximation -- The Analysis of the Exploration of Efficiency of Investment Projects of Arbitrary Duration (within Brusov–Filatova–Orekhova Theory) -- Investment Models with Uniform Debt Repayment and Their Application -- Whether It Is Possible to Increase Taxing and Conserve a Good Investment Climate in the Country?- Whether It Is Possible to Increase the Investment Efficiency, Increasing Tax on Profit Rate? An Abnormal Influence of Growth of Tax on Profit Rate on the Efficiency of the Investment -- Optimizing of the Investment Structure of the Telecommunication Sector Company -- The Golden Age of the Company (Three Colors of Company's Time) -- Conclusion.