Question

How to solve completing the square method questions

Answer 1

Steps are following :-

1.) Transfer the constant term in R.HS.

2.) Divide the whole equation by the coficient of x^2

3.) Add the square of half of the coficient of x in both sides.

Now you will get perfect square..


For Example :-

2x^2 + 10x + 12 = 0

=> 2x^2 +10x = - 12

=> x^2 + 5x = - 6

=> x^2 + 5x + (5/2)^2 = - 6+(5/2)^2

=> (x +5/2)^2 = - 6 + 25/4

=> (x+5/2)^2 = 1/4

=> x + 5/2 = +- 1/2

=> x = 5/2 + - 1/2


x = 2 and 3

Answer 2

It's simple 

    take any Quadratic Equation such as: x^2 - 4x +4 = 0

we have, x^2 - 4x +4 =0
           so, x^2 -4x = -4
                we have to show it in the form of a whole square

so, (x)^2 -2(2)(x) + (2)^2 = -4 + (2)^2

 becoz (a-b)^2 = a^2 + b^2 - 2ab
 where we took a = x and b = 2

so, (x-2)^2 = 0
        x-2 = 0
   so, x = 2