what is 7x[4/12x(4+8)]-1
$${\mathtt{7}}{\mathtt{\,\times\,}}\left(\right){\mathtt{\,-\,}}{\mathtt{1}} = {\mathtt{\,-\,}}{\mathtt{1}}{\mathtt{\,\small\textbf+\,}}{\mathtt{7}}{\mathtt{\,\times\,}}\left(\right)$$
BUT, what is your x value??