The given expression is
[tex]18\colon(-\frac{2}{3})\times4\colon(-7)\times(-3)\colon(\frac{1}{4})[/tex]First, we solve the divisions, to do it, we flip the second factor of each division to transform the operation into a product
[tex]18\cdot(-\frac{3}{2})\times4\cdot\frac{1}{-7}\times(-3)\cdot4[/tex]Then, we solve the products
[tex]-\frac{18\cdot3\cdot4\cdot1\cdot3\cdot4}{2\cdot7}=\frac{2592}{14}=\frac{1296}{7}[/tex]