A = | 4X^2 + 12X + 9 | => simplifying =>

A = 4×| X^2 + 3X + 9/4 | =>

A = 2^2×| X + 3/2|^2

√[2^2×|X + 3/2|^2] = 2×| X + 3/2 |

Perimeter of square is

4×[2×| X + 3/2 |] => P = | 8X + 12| cm

pa brainliest ty

Answer:

Simple math.

First of all, you need to factor the expression

4x² +12x + 9

This will be a trial and error method.

Since you have a given choice, it will be obvious to know the right answer. We are talking about squares here

So

(2x + 3)  will be the right one. Since only the 2x times itself will give us 4x^2

Remember Area of square is equal to side squared. or A = a^2

let's check:

         2x + 3

         2x + 3

-------------------

         6x + 9  -> (2x + 3) * 3

4x^2 + 6x        -> (2x + 3) * 2x

-------------------

4x^2 + 12x + 9 -> correct

Step-by-step explanation:

goodluck