Explanation:
Equation
An equation is a
mathematical statement that asserts the equality of two expressions. Equations
consist of the expressions that have to be equal on opposite sides of an equal
sign as in

Properties
If an equation in algebra is known to be true, the following
operations may be used to produce another true equation:
1.
Any real number can be added to both sides.
2.
Any real number can be subtracted from both sides.
3.
Any real number can be multiplied to both sides.
4.
Any non-zero real number can divide both sides.
5.
Some functions can be applied to both sides. Caution
must be exercised to ensure that the operation does not cause missing or extraneous solutions. For example, the
equation y*x=x has 2 solutions: y=1 and x=0. Dividing both sides by x
"simplifies" the equation to y=1, but the second solution is lost.
http://en.wikipedia.org/wiki/Equation
Equation solving
In mathematics, to solve an equation is to find what values
(numbers, functions, sets, etc.) fulfill a condition stated in the form of an equation (two expressions related by equality). These expressions
contain one or more unknowns, which are free variables for which values are, sought that cause the condition to be
fulfilled.
A solution of the equation is an
assignment of expressions to the unknowns that satisfies the equation; in other
words, expressions such that, when they are substituted for the unknowns, the
equation becomes a tautology (a provably true statement). (Our solved example
in mathguru.com uses this concept)
http://en.wikipedia.org/wiki/Equation_solving
The above explanation is copied from
Wikipedia, the free encyclopedia and is remixed as allowed under the Creative
Commons Attribution- ShareAlike 3.0 Unported License.