Direction ratios of a line are $-18,12,-4$
Direction cosines of line are $-\frac{18}{\sqrt{{18}^2+{12}^2+4^2}},\frac{12}{\sqrt{{18}^2+{12}^2+4^2}},-\frac{4}{\sqrt{{18}^2+{12}^2+4^2}}$
Hence, direction cosines of line are $-\frac{9}{11},\frac{6}{11},-\frac{2}{11}$.
OR
The cartesian equation of the line which passes through the point $\left(-2,4,-5\right)$ and is parallel to the line $\frac{\mathit{x}+3}{3}=\frac{\mathit{y}-4}{-5}=\frac{\mathit{z}+8}{6}$ is $\frac{\mathit{x}+2}{3}=\frac{\mathit{y}-4}{-5}=\frac{\mathit{z}+5}{6}$.