Linear Equation ( One Variable )

One variable

A linear equation in one unknown x may always be rewritten

ax=b.

If a ≠ 0, there is a unique solution

x=\frac{b}{a}.

If a = 0, then either the equation does not have any solution, if b ≠ 0 (it is inconsistent), or every number is a solution, if b is also zero.

~ source : http://en.wikipedia.org/wiki/Linear_equation