TY JOUR TI APPROBATION OF ECONOMIC AND MATHEMATICAL MODELS IN ACTIVITY OF THE ENTERPRISES WITH THE HELP OF USING MICROSOFT EXCEL AND MATHCAD PROGRAMS KW economic and mathematical modeling KW Monge-Cantarovitch's problem KW optimization model KW planning JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Chikina, E.D. AU Shevchenko, M.. PY 2016 IS 1 PB Belgorod State Technological University named after V.G. Shukhov