An equation is a mathematical statement such that the expression on the left
side of the equals sign (=) has the same value as the expression on the right side.
An example of an equation is 222 + 222 = 444.
One of the terms in an equation may not be know and needs to be determined. Often
this unknown term is represented by a letter such as x. (e.g. 222 + x = 444).
The solution of an equation is finding the value of the unknown x. To find the
value of x we can use the subtractive equation property which says: The two sides of an
equation remain equal if the same number is subtracted from each side.
Example:
500 + x = 1200
500 + x - 500 = 1200 - 500
0 + x = 700
x = 700
Check the answer by substituting the answer (700) back into the equation.
500 + 700 = 1200