Chapter I : Linear Equations in two variables in two variables

3. Elimination by equating coefficients:

Let us consider a system of equations:

x - 5y = 11 ----------(1)
2x + 3y = -4 ---------(2)

Multiplying equation (1) by 2 and then subtracting eq. (2) from this we get

Or, y = -2

Patting y = -2 in eq (1) we get

x = -5 (-2) = 11

Or, x + 10 = 11

Or, x = 1

 

Subjects Maths (Part-1) by Mr. M. P. Keshari
Chapter 1 Linear Equations in Two Variables
Chapter 2 HCF and LCM
Chapter 3 Rational Expression
Chapter 4 Quadratic Equations
Chapter 5 Arithmetic Progressions
Chapter 6 Instalments
Chapter 7 Income Tax
Chapter 8 Similar Triangles