Advice 1: As the formula expressing a variable

The concept "formula" is widely used not only in the exact Sciences, but in relation to mathematics the word often denotes a certain identity. This is a recording of two sequences of mathematical operations applied to one or more variables, between which there is an equal sign. To Express one variable identities through all the others, it is necessary to convert this equation so that the left part remained only that variable.
As the formula expressing a variable
Start the conversion, for example, getting rid of fractions, if they are in the original formula. Both side of the equation, multiply by the common denominator. For example, the formula 3*Y = √X/2 after this step should get 6*Y = √X.
If the expression in one side of the equation contains a root of any degree, get rid of him, elevating both sides of the identities in degree equal to the index of the root. For the example given above, this action must be expressed in the transformation formula like the following: 36*Y2 = operation X. Sometimes this step is easier to produce action from the previous step.
Convert an expression so that all members of the identity that contains the desired variable, was in the left side of the equation. For example, if the formula has the form 36*Y-X*Y+5=X and you are interested in the variable X, it is enough to swap the left and right halves of identity. But if you need to Express Y, then the formula resulting from this action needs to get 36*Y-X*Y=X-5.
Simplify the expression in the left part of the formula to the desired variable was one of the factors. For example, the formula from the previous step it is possible to make so: Y*(36-X)=X-5.
Divide the expressions on both sides of the equal sign to the variable factors you are interested in. As a result, in the left side of the identity must remain only that variable. Used the above example after this step has acquired the following form: Y = (X-5)/(36-X).
If the required variable in the result of all the changes will be elevated to some degree, then get rid of degree root from both parts of the formula. For example, the formula from the second step to this phase transformation should acquire the form Y2=X/36. And her final look should be like this: Y=√X/6.

Advice 2: What is variable in math

The first thing children learn in school algebra course are variables and numbers. Contained in the equations, the unknown variable is usually denoted by an arbitrary letter. When solving this problem it is necessary to find the value of this variable.
What is variable in math


The main indicator variable is that it is not the number and letter. Under the symbol often hides a certain value. The variable got its name due to the fact that it has a different value depending on the equation. As a rule, any letter of the alphabet can be used as a label for this element. For example, if you know that you have 5 rubles, and you want to buy apples that cost 35 cents, a finite number of apples that can be purchased, is indicated by a letter (e.g. "C").

Example usage

If there is a variable that was chosen at your discretion, it is necessary to make algebraic equation. It will relate the known and unknown quantities and the relationship between them. This expression will include numbers, variables, and one algebraic operation. It is important to note that the expression will contain an equal sign.

The full equation contains the value of the expression as a whole. It is separated from the rest of the equation is the equal sign. In the previous example with the apples 0.35 or 35 cents, multiplied by "C" is an expression. To create the full equation, it is necessary to record the following:

0.35*C = 5.00

Monomial expressions

There are two main classification of expressions: monomials and polynomials. The monomials are a single variable, a number or product of a variable and number. Furthermore, the expression of several variables or expressions with indicators is also monorom. For example, the number 7, the variable x, and the product 7*x is monom. Expressions involving indices, including x^2 or 3x^2y^3 terms.


Polynomials are expressions that include a combination of addition or subtraction of two or more monomials. Any type of terms, including numbers, variables, or expressions with numbers and variables, can be included in the polynomial. For example, the expression x+7 is a polynomial, which put together monom and monom x 7. 3x^2 is also a polynomial. 10x+3xy-2y^2 is an example of a polynomial that combines three single term using addition and subtraction.

The dependent and independent variables

In mathematics, independent variables are unknown, which define the other part of the equation. They are separate expressions and do not change with other variables.

Values of the dependent variables are identified using independent. Their values are often determined empirically.
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