Answer
$-5x^{3}+10x^{2}-\displaystyle \frac{3}{5}x+8$
Work Step by Step
Using the property: $\displaystyle \quad\frac{A+B}{C}=\frac{A}{C}+\frac{B}{C},$
$\displaystyle \frac{25x^{8}-50x^{7}+3x^{6}-40x^{5}}{-5x^{5}}=\frac{25x^{8}}{-5x^{5}}-\frac{50x^{7}}{-5x^{5}}+\frac{3x^{6}}{-5x^{5}}-\frac{40x^{5}}{-5x^{5}}$
= $-5x^{3}+10x^{2}-\displaystyle \frac{3}{5}x+8$
