Equation facts for kids
A mathematical equation is an expression containing two mathematical objects connected by an equals sign (=) . 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 
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:
- 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:
The second kind is often used to solve problems in which finding the value of some variables is involved. For example, if
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
Images for kids
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The first use of an equals sign, equivalent to 14x + 15 = 71 in modern notation. From The Whetstone of Witte by Robert Recorde of Wales (1557).
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The Nine Chapters on the Mathematical Art is an anonymous 2nd-century Chinese book proposing a method of resolution for linear equations.
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A conic section is the intersection of a plane and a cone of revolution.
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A strange attractor, which arises when solving a certain differential equation
See also
In Spanish: Ecuación para niños
