## Introductory Algebra for College Students (7th Edition)

An equation is a mathematical statement in which it is claimed that two mathematical expressions are equal. An equation is written in the form (expression on the left side) = (expression on the right side of the equality sign), that is, the two expressions are on either side of one equality sign (=). Examples: $2x=5+7x,$ $x-2y+9=3,$ $\displaystyle \frac{n+3}{7}-1=0$