Cho (4x^2+2x-18)^2-(4x2+2x)^2=m.(4x^2+2x-9)Khi đó giá trị

Ta có
$\left({{{4}{x}^{2}{+}{2}{x}{-}{18}}}\right){2}{-}\left({{{4}{x}^{2}{+}{2}{x}}}\right){2}$
${=}\left({{{4}{x}^{2}{+}{2}{x}{-}{18}{+}{4}{x}^{2}{+}{2}{x}}}\right)\left({{{4}{x}^{2}{+}{2}{x}{-}{18}{-}{4}{x}^{2}{-}{2}{x}}}\right)$
${=}\left({{{8}{x}^{2}{+}{4}{x}{-}{18}}}\right)\left({{{-}{18}}}\right)$
${=}{2}\left({{{4}{x}^{2}{+}{2}{x}{-}{9}}}\right)\left({{{-}{18}}}\right)$
${=}\left({{{-}{36}}}\right)\left({{{4}{x}^{2}{+}{2}{x}{-}{9}}}\right)$$\Rightarrow$${m}{=}{-}{36}$
Đáp án cần chọn là: C