RS Aggarwal Solutions for Class 7 Chapter 7 Includes Equation; 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 a x + b = 0 display style ax+b=0 and are solved using basic algebraic operations. An identity equation is true for all values of the variable. The linear equations in one variable is an equation which is expressed in the form of ax+b = 0, where a and b are two integers, and x is a variable and has only one solution. 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. The equation is a statement of equality which contains one or more unknown quantities or variables. Other related concepts are rules for solving an equation, transposition and conversion of word problems into equations for getting the required result.