$\frac{\left(4x-1\right)\left(x-3\right)}{\left(5x-1\right)\left(x+5\right)}\cdot\frac{\left(5x-2\right)}{\left(x+9\right)\left(x-3\right)}\cdot\frac{\left(x+9\right)\left(x-4\right)}{\left(4x-1\right)}$

$\frac{\left(4x-1\right)\left(x-3\right)\left(5x-2\right)\left(x+9\right)\left(x-4\right)}{\left(5x-2\right)\left(x+5\right)\left(x+9\right)\left(x-3\right)\left(4x-1\right)}$

Look for 1s.

$\frac { x - 4 } { x + 5 }$

$\frac{x^2-9}{x^2+6x+9}\cdot\frac{x^2+4}{x^2-x-6}$

$6 \text { by } \frac { x + 1 } { x + 1 }$

$\frac{6\left(x+1\right)}{x+1}+\frac{3}{x+1}$

$\frac { 6 x + 9 } { x + 1 }$

Factor the denominator of the term on the right to help you find a common denominator.