Answer:
16x² + 72x + 81
Step-by-step explanation:
The area of a square is [tex]s^2[/tex], where s = side. In this case, we're given the side length as 4x + 9.
- [tex](4x+9)^2 = (4x+9)(4x+9)[/tex]
- [tex](4x+9)(4x+9)=(4x)(4x)+(4x)(9)+(9)(4x)+(9)(9)[/tex]
- [tex]16x^2+36x+36x+81[/tex]
- [tex]16x^2+72x+81[/tex]
Therefore, the answer is 16x² + 72x + 81.
