Factorise the following : 4x² + 20x + 25

Solution:

Given, the polynomial is 4x² + 20x + 25 -------------- (1)

We have to factorise the polynomial.

Using the algebraic identity,

(a + b)² = a² + 2ab + b² ---------------- (2)

On comparing (1) and (2),

a² = 4x²

a = 2x

b² = 25

b = 5

2ab = 20x

ab = 10x

Now, (a + b)² = (2x + 5)²

Therefore, the factors are (2x + 5) and (2x + 5).

✦ Try This: Factorise the following : 9x² + 12x - 3

☛ Also Check: NCERT Solutions for Class 9 Maths Chapter 2

NCERT Exemplar Class 9 Maths Exercise 2.3 Problem 26(i)

Factorise the following : 4x² + 20x + 25

Summary:

On factorising 4x² + 20x + 25 using the algebraic identity we get the factors as (2x + 5)²

☛ Related Questions:

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• Factorise (2x + 1/3)² - (x - 1/2)²
• Factorise 9x² - 12x + 3