Question

write the identity used in the following (2a+1)2​

Answer 1

This is the answer

${a + b}^{2}$

Answer 2

Here, identity used is:

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

Now,

${(2a + 1)}^{2} = {(2a)}^{2} + {1}^{2} + 2.2a.1$

$= 4 {a}^{2} + 1 + 4a$

OR

$= 4 {a}^{2} + 4a + 1$

Hence, this is your answer