Question

(5x mũ 2 +2x +1)×(-2x)-(x+3) ×(x-3)×5x

Answer 1

\(\Leftrightarrow-10x^3-4x^2-2x-\left(x^2+9\right)\cdot5x\)

\(=-10x^3-4x^2-2x-10x^3-45x=-4x^2-47x\)

Answer 2

 \(\left(5x^2+2x+1\right)\left(-2x\right)-\left(x+3\right)\left(x-3\right).5x\\ =-10x^3-4x^2-2x-\left(x^2-3^2\right).5x\\ =-10x^3-4x^2-2x-\left(5x^3-45x\right)\\ =-10x^3-4x^2-2x-5x^3+45x\\ =-15x^3-4x^2+33x\)