kidzsearch.com > wiki
Equation
KidzSearch Safe Wikipedia for Kids.
For a chemical type of equation, see Chemical equation.
A mathematical equation is an expression containing two mathematical objects connected by an equals sign (=) .^{[1]}^{[2]}^{[3]}^{[4]} The equals sign says that both sides are exactly equal, or of the same value. An equation can be as simple as x=0, or as complex as [math]4(3y^{99}) +76=42+3x[/math] or harder.
There are two kinds of mathematical equations:
 The kind of equation that is either true or false; these are also called identities. For example:
 [math]2 \cdot (x+4)=2x+8 \rightarrow \text{true}[/math]
 The kind of equation that is only true for certain values of the variable(s). The equation is only true if the variable(s) have that value. For example:
 [math]2 \cdot x=8 \rightarrow x=4[/math]
The second kind is often used to solve problems in which finding the value of some variables is involved. For example, if
 [math] 2x = 8, \, x = \frac{8}{2} = 4. [/math]
The second kind of equation is used in algebra. For example, to solve the equation 2x = 8 for x, one would follow an algebraic rule to find that x = 4.
Types of equations
Equations can be classified by the types of operations and quantities involved. For example:
 An algebraic equation is an equation in which both sides are polynomials. These are further classified by degree:
 Linear equation for degree one
 Quadratic equation for degree two
 Cubic equation for degree three
 Quartic equation for degree four
 Quintic equation for degree five
 A Diophantine equation is an equation where the unknowns are required to be integers
 A differential equation is a functional equation involving derivatives of the unknown functions, which include:
Related pages
References
 ↑ "Compendium of Mathematical Symbols" (in enUS). 20200301. https://mathvault.ca/hub/highermath/mathsymbols/.
 ↑ "Equations and Formulas". https://www.mathsisfun.com/algebra/equationformula.html.
 ↑ "A statement of equality between two expressions. Equations are of two types, identities and conditional equations (or usually simply "equations")". « Equation », in Mathematics Dictionary, Glenn James et Robert C. James (éd.), Van Nostrand, 1968, 3 ed. 1st ed. 1948, p. 131.
 ↑ Une équation est une égalité entre deux expressions mathématiques, donc une formule de la forme A = B, où les deux membres A et B de l'équation sont des expressions où figurent une ou plusieurs variables, représentées par des lettres. ÉQUATION, mathématique  Encyclopædia Universalis
