Using the quadratic expansion formula:

[math](a + b)^2 = a^2 + 2ab + b^2[/math]

[math](2x + 3)^2 = (2x)^2 + 2(2x)(3) + 3^2[/math]

[math]= 4x^2 + 12x + 9[/math]

Therefore, our answer is [math]4x^2 + 12x + 9[/math]