Each school student has to learn to remove the brackets in the equation. Implementation of this procedure is important for the solution of the mathematical, physical and other tasks demanding at least the minimum calculations.
Instruction
1. So, you have the equation. In some member of equation there is an expression in brackets. To remove the brackets, look at the sign before brackets. If there is a plus, at dehiscence of brackets in record of expression nothing will exchange: just remove brackets. If there is a minus sign, at removal of brackets it is necessary to change all signs in the expression standing initially in brackets for opposite. For example, - (2kh-3)=-2kh +3.
2. Multiplication of two brackets. If at the equation there is a work of two brackets, removal of brackets happens by the standard rule. Each member of the first bracket is multiplied with each member of the second bracket. The received numbers are summarized. At the same time the work of two ""pluses"" or two ""minuses"" gives composed the sign ""plus"" and if multipliers have different signs, then composed receives the sign ""minus"". Let's review an example. (the 5th +1) (3kh-4) =5х*3х-5х*4+1*3х-1*4=15х^2-20х +3х-4=15х^2-17х-4.
3. Removal of brackets sometimes also call construction of expression in degree. Formulas of squaring and in a cube should be known by heart and to remember. (a+b) ^2=a^2+2ab+b^2(a-b) ^2=a^2-2ab+b^2(a+b) ^3=a^3+3a^2*b+3ab^2+b^3(a-b) ^3=a^3-3a^2*b+3ab^2-b^3Формулы constructions of expression in degree more than three can be received by means of Pascal's triangle.