A linear equation is one which when graphed yields a straight line. This is true if the linear equation has two unknowns or variables. The solution to a linear equation is an ordered pair. The standard form of a linear equation in two variables is a₁x + a₂y = b, where a₁, a₂ and b are constants and x and y are the variables. The ordered pair (x,y) is a solution to the linear equation. A linear equation in n variables x₁, x₂, x₃,...x_n is expressed as a₁x₁ + a₂x₂ +...a_nx_n = b, where a₁, a₂,...a_n and b are real constants. The solution to such an equation is a sequence of n numbers s₁, s₂,...s_n such that the equation is satisfied when x₁ = s₁, x₂ = s₂,...x_n = s_n. A solution set is a set...