Skills Handbook - Operations With Rational Expressions - Exercises - Page 984: 16

$$4$$

First, find and divide out any common factors: $$\frac{7x}{8}\times \frac{64}{14x}=\bigg(\frac{7\times x}{8}\bigg)\times \bigg(\frac{8\times 2\times 2\times 2}{2\times 7\times x}\bigg).$$ In this case, cancel the factors $7$, $x$, $8$, and $2$ and the result is $$ 2\times 2=4.$$