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 -
2 - (- 6) = 4. 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. - 2 + x = 4). 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. We may also use
the additive equation property which says: The two sides of an
equation remain equal if the same number is added to each side.
x - (- 5) = 4 x + 5 = 4 x + 5 - 5 = 4 - 5 x + 0 = - 1 x = - 1
Check the answer by substituting the answer ( - 1) back into the
equation. - 1 - ( - 5) = 4