Class 8 Maths Linear Equations in One Variable Introduction

Introduction to Linear Equations

A linear equation is an algebraic equation in which each term is either a constant or the product of a constant and a variable. This variable is always single power form. A simple example of a linear equation with only one variable, x, may be written in the form: ax + b = 0, where a and b are constants and a ≠ 0.

These equations are called Linear Equations in one variable. Examples:

• 2x
• 5/4 (x-4)
• 3y-7
• x2 + 1 is an non-linear as the variable has power more than 1.
• 5xy + 10 is not a linear equation in one variable as there are two variables

For example, if a child has 2 chocolates of 10 rupees and a 20 rupee note, the total value can be calculated using the equation 2x + 20 = 2 * 10 + 20 = 40. Here ‘x’ is variable and is the value of the chocolate. Another example, one child buys three toys (costing rupees 20 each) from a shopkeeper but gives only 5 rupees to him. The total value of items with child will be 3y - 5, where y is the cost of one toy. .