$${\mathtt{\,-\,}}{\frac{{\mathtt{7}}}{{\mathtt{2}}}}{\mathtt{\,\times\,}}\left({\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{6}}}{{\mathtt{7}}}}\right){\mathtt{\,-\,}}{\mathtt{3}}$$
First you distribute the -7/2.
$${\mathtt{\,-\,}}\left({\frac{{\mathtt{7}}}{{\mathtt{2}}}}{\mathtt{\,\times\,}}\left({\mathtt{2}}\right)\right) = -{\mathtt{7}}$$
$${\mathtt{\,-\,}}\left({\frac{{\mathtt{7}}}{{\mathtt{2}}}}{\mathtt{\,\times\,}}\left({\frac{{\mathtt{6}}}{{\mathtt{7}}}}\right)\right) = -{\mathtt{3}}$$
This makes the equation into something a bit more legible.
$$\left({\mathtt{\,-\,}}{\mathtt{7}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{3}}\right){\mathtt{\,-\,}}{\mathtt{3}}$$
Then you just subtract 3.
$$\left({\mathtt{\,-\,}}{\mathtt{7}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{3}}{\mathtt{\,-\,}}{\mathtt{3}}\right)$$
$$\left({\mathtt{\,-\,}}{\mathtt{7}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{6}}\right)$$
At this point you can drop the parentheses and you have your most simplified answer: -7x - 6