Answer:
-23x^3+20x^4+25x^2+84x-84
Explanation:
1 Expand by distributing sum groups.
4x^2(3x+5x^2-6)-7x(3x+5x^2-6)+14(3x+5x^2-6)
2 Expand by distributing terms.
12x^3+20x^4-24x^2-7x(3x+5x^2-6)+14(3x+5x^2-6)
3 Expand by distributing terms.
12x^3+20x^4-24x^2-(21x^2+35x^3-42x)+14(3x+5x^2-6)
4 Expand by distributing terms.
12x^3+20x^4-24x^2-(21x^2+35x^3-42x)+42x+70x^2-84
5 Remove parentheses.
12x^3+20x^4-24x^2-21x^2-35x^3+42x+42x+70x^2-84
6 Collect like terms.
(12x^3-35x^3)+20x^4+(-24x^2-21x^2+70x^2)+(42x+42x)-84
7 Simplify.
-23x^3+20x^4+25x^2+84x-84