An equation of the type ax = b, where a and b are real constants and x is an unknown, is called a linear equation in x. If x_{1}, x_{2} …, x_{n} are unknowns (called variables) then a relation of the type
where a_{1}, …, a_{n} and b are given real constants is called a linear equation in x_{1},… , x_{n}. The constants a_{1}, …, a_{n} are called the coefficients of the variables x_{1}, …, x_{n} respectively. By a solution of equation (10.1) is meant a set of values of x_{1}, …, x_{n} which satisfy it.
Example 10.1.
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