# Question #f41ff

##### 2 Answers

Mar 12, 2017

#### Explanation:

If

#A = color(blue)(9)^2-4(color(blue)(9)) = 81-36 = 45#

So

#x^2-4x=45#

Add

#x^2-4x+4 = 49#

That is:

#(x-2)^2 = 7^2#

Hence:

#x-2 = +-7#

Add

#x = 2+-7#

That is:

#x = 9" "# or#" "x = -5#

So

So

Mar 14, 2017

#### Explanation:

By what is given, **Quadr. Eqn.,**

Knowing that, in the **Quadr. Eqn.**

**Sum of Roots**

Hence, **Respected George C. Sir** has already derived!

**Enjoy Maths.!**