Class 6 Chapter 11 Algebra | Free NCERT Solutions

Introduction:

Variable:  The word variable means something that can vary.

The value of a variable is not fixed. It can take different values. One may use any letter as m, l, p, x, y, z etc. to show a variable.

Variables are numbers, although their value is not fixed. We can do the operations of addition, subtraction, multiplication and division on them just as in the case of fixed numbers. Using different operations we can form expressions with variables like x- 3, x+3, 2n, 5m, 2y+3, 3l-5, p/3 etc.

Equation: An equation is a condition on a variable.

An equation has two sides, LHS and RHS, between them is the (=) sign.

Solution:  The LHS of an equation is equal to its RHS only for a definite value of the variable in the equation. We say that this definite value of the variable satisfies the equation. This value itself is called the solution of the equation.