## Elementary Technical Mathematics

$$-32x^2+8x^3-12x^4.$$
We simplify by distributing $-4x^2$ as follows: $$-4x^2(8-2x+3x^2)=-4x^2(8)-4x^2(-2x)-4x^2(3x^2)\\ = -32x^2+8x^3-12x^4.$$