RS Aggarwal Solutions for Class 9 Chapter 4 “Linear-equations-in-two-variables”, an equation of the form ax + by + c = 0, where a, b and c are real numbers, such that a and b are not both zero, is called a linear equation in two variables. The equation is called linear because the equation is of the first degree. A solution is an ordered pair of real numbers which satisfies the equation. Various methods like elimination method, substitution method and graphing method can be made use of to solve the linear equations in two variables. This Chapter contains exercise wise problems which are solved using concepts like Linear Equations in Two Variables and graph of a linear equation in two variables.