A linear equation looks like any other equation. It is made up of two expressions set equal to each other. When you find pairs of values that make the linear equation true and plot those pairs on a coordinate grid, all of the points for anyone equation lies on the same line. A linear equation is an equation of a straight line, written in one variable. The only power of the variable is 1. Linear equations in one variable may take the form ax + b = 0 display style ax+b=0 ax+b=0 and are solved using basic algebraic operations. An identity equation is true for all values of the variable. For example, 2x+3=8 is a linear equation having a single variable in it. Therefore, this equation has only one solution, which is x = 5/2.