Gauss's method is one of the basic principles of the solution of a system of the linear equations. Its advantage is that it does not demand a kvadratichnost of an initial matrix or preliminary calculation of its determinant.

Ethyl alcohol is well-known, it is a part of all alcoholic beverages. The appearance of ethanol – transparent colourless liquid with a pungent characteristic smell, is a little lighter than water. Cases of a serious poisoning when they take other organic liquids for ethanol, including such poisonous as methyl alcohol are frequent. Special danger and insidiousness of methanol that the use even of small amount of this alcohol can cause a blindness or a lethal outcome, and on appearance, a smell, density and taste it we will practically not distinguish from ethanol.

Soda is a substance which familiarly much. It is practically in each house. But at the same time not all know what is it and as it is possible to apply it. And especially seldom who thinks that soda is the most real chemical.

Presently people quite often deal with the intake of alcohol and drinks with its contents. Alcohol appeared in immemorial times. From the chemical point of view it represents ethyl alcohol – ethanol, colourless liquid which has a specific smell and has flying properties. Its molecular formula – C2-H5-OH, or CH3-CH2-OH. Other alcohols and aldehydes are substitutes of alcohol and are dangerous to an organism. Ethanol is used also for needs of medicine. As to distinguish it – about it read further.