In mathematics is a statement of an , an equation containing one or more. Solving consists of determining which values of the variables make the equality true. Variables are also called and unknowns the values of the unknowns which satisfy the equality are called solutions of the equation. There are two kinds of equations: identity equations and conditional equations. An identity equation is true for all values of the variable. A conditional equation is true for only particular values of the variables. So, every identity is an equation first.