Question

x² - 20 x - 81 in breaking the middle term ​

Answer 1

Answer:

$\tt{(x-9)(x-9)}$

Step-by-step explanation:

The question you had asked can't be split up into middle term. So, the question you asked can only be done through the method of quadratic formula or completing the square method.

Correct Question:

$\rm{Solve: \: x^2-18x+81 }$ by factorisation method.

★ Concept :-

Here, the concept of splitting the middle term is used. This method is also called as factorisation method.

Let's do it!

$\bf{x^2-18x+81 }$

-18x( middle term) can be split into -9x-9x [because -9x-9x = 81 which is nothing but the constant value.]

$\implies\bf{x^2-9x-9x+81 }$

$\implies\bf{x(x-9)-9(x-9)}$

$\implies\bf{(x-9)(x-9)}$

Answer 2

Answer:

(x-9)(x-9)

Correct question:-

x² - 18x + 81 by factorisation method.

Explanation:-

x² -9x -9x +81

x(x-9)-9(x-9)

(x-9)(x-9) is correct answer