 In algebra, an algebraic equation (polynomial equation) is an equation which is of the form

A = B

Here, A and B are the polynomials with coefficients. In other words, an equation is of the form of a polynomial with a finite number of terms and it is equated to zero is known as algebraic equations. The expression in the equations may be either monomial, binomial, trinomial or polynomial. Let’s consider an equation

3x – 5 = 4

Here the equation is of the binomial form where 3 is the coefficient of x, x is a variable and 4 and 5 are the constants.

In order to convert into proper algebraic expressions, equate this expression to zero and it becomes,

3x – 5 – 4 = 0 (or) 3x – 9 = 0

If the algebraic equation is of the higher degree of 2 is known as a quadratic equationand is of the form ax2+ bx + c = 0. There are several methods to solve quadratic expressions. They are

• Factoring method
• Square root method
• Completing the square method

## Factoring Method

Consider an equation x2 -4x – 12 = 0

In this method, the equation can be factorised into (x-6)(x+2) = 0

When you equate this to zero, it becomes

(x-6) = 0 or (x+2)=0

x=6 or x=-2

## Square Root Method

The square root method is used when the term bx = 0

For example, x2 – 1 = 24

Here, the term bx = 0

To use this method, isolate the xterm on the left side and add +1 on both the sides to eliminate the constant term and it becomes x2 = 25

Now, take square roots on both the sides, to find the value of x

Therefore, x = ± 5

This can be written as x = +5 or x = -5

## Completing the Square Method

The procedure to solve the quadratic expression as follows

• Divide all the terms by “a” (coefficients of x2)
• Move the term c/a to the right side of the equation
• Now complete the square on the left side of the expression.
• To balance the expression, add the same number to the right side of the expression
• Take square root on both the sides
• Finally, to find the value of x, subtract or add the number that remains on the left side of the equation on both sides.