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 22 + 22 = 44.
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. 22 + x = 44).
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:
50 + x = 120
50 + x - 50 = 120 - 50
0 + x = 70
x = 70
Check the answer by substituting the answer (70) back into the equation.
50 + 70 = 120