# CBSE Class 7th Maths

## Simple Equations

### Simple Equations

Equations involving only a linear polynomial are called simple equations.
e.g. 4x + 5 = 65, 10y – 20 = 50

In an equation, there is always an equality sign.

A Simple Equation remains the same when the expression in the left and right are interchanged.

The value of a variable, which makes the equation a true statement is called the solution of a linear equation.
e.g. 5x – 12 = -2 is a equation
L.H.S = 5x – 12 = 5 × 2 – 12 = 10 – 12 = -2
L.H.S = R.H.S

#### Variables and Expressions

Variable is a quantity that can take any value, its value is not fixed. It is a symbol for a number whose value is unknown yet.

Expressions are formed by performing operations like addition, subtraction, multiplication and division on the variables.

Example: 6x – 3 is an expression in variable x.

### Algebraic Equation

An equation is a condition on a variable such that two expressions in the variable should have equal value.

Example: 8x8=16 is an equation.

The value of the variable in an equation for which the equation is satisfied is called the solution of the equation.​

​​​​​​Example: The solution for the equation 2x3=5 is x=4.