Distribute sum groups
2x^2(3x^2 + 9x + 3) - 5x(3x^2 + 9x + 3)
Distribute
6x^4 + 18x^3 + 6x^2 - 5x(3x^2 + 9x + 3)
Distribute
6x^4 + 18x^3 + 6x^2 - (15x^3 + 45x^2 + 15x)
Simplify brackets
6x^4 + 18x^3 + 6x^2 - 15x^3 - 45x^2 - 15x
Collect like terms
6x^4 + (18x^3 - 15x^3) + (6x^2 - 45x^2 - 45x^2) - 15x
Simplify
Answer: A) 6x^4 + 3x^3 - 39x^2 - 15x