Question

can anyone explain this which I Highlighted? can anyone buddy​

Answer 1

Answer:

apply (a+b)²=a²+2ab+b² formula

here a=2k, b=1

(2k+1)²=(2k)²+2(2k)(1)+1²

=4k²+4k+1

Answer 2

Step-by-step explanation:

Given:

${(2k + 1)}^{2}$

To find: How

$4 {k}^{2} + 4k + 1$

Solution:

We know that

$\bold{( {x + y)}^{2} = {x}^{2} + 2xy + {y}^{2} }$

Here,In

$( {2k + 1)}^{2} \\\\ x = 2k \\ \\ y = 1$

apply in the identity

$( {2k + 1)}^{2} = ( {2k)}^{2} + 2(2k)(1) + ( {1)}^{2} \\ \\ ( {2k + 1)}^{2} = 4 {k}^{2} + 4k + 1$

This way one can achieve the desired result.

I hope it helps you.