Given sides of the triangle:
- 3x^2 + 8,
- 2x^2 + x, and
- x - 3.
We know that the perimeter of a triangle is the sum of all the sides of a triangle.
Perimeter of the triangle,
= 3x^2 + 8 + 2x^2 + x + x - 3
= 3x^2 + 2x^2 + x + x + 8 - 3
= 5x^2 + 2x + 5
Therefore, the perimeter of the triangle is 5x^2 + 2x + 5. Hence, the option A is the correct answer.