Multiplying and Dividing Rational Numbers

$$\frac{8x^2y^7}{3x^3y^3}$$  

$$\frac{8y^4}{3x}$$  

$$\frac{40x^2y^7}{30x^3y^3}$$  

$$\frac{12y^{10}}{50x^5}$$  

$$\frac{2x^4+4x^2-72x^2-144x}{4x^3+8x^2-144x-288}$$

$$1$$

$$\frac{x}{2}$$

Can't be simplified

$$\frac{y^{\ 4}}{2x^2}$$

$$\frac{9y^8}{2x^4}$$

$$\frac{2x^2}{y^{\ 4}}$$

Can't be simplified

$$\frac{4\left(x-4\right)}{\left(x+5\right)}$$

$$\frac{\left(x+4\right)^2\left(x-4\right)}{16\left(x+5\right)}$$

Can't be simplified

$$\frac{\left(x+5\right)}{4\left(x-4\right)\ }$$

$$\frac{4\left(x-6\right)}{\left(x-4\right)\left(x-2\right)}$$  

$$\frac{\left(x-4\right)\left(x-2\right)}{4\left(x-6\right)}$$  

$$\frac{x-6}{x-2}$$  

$$\frac{4}{x-4}$$