17+3x-11=0

$${\mathtt{17}}{\mathtt{\,\small\textbf+\,}}{\mathtt{3}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{11}} = {\mathtt{0}} \Rightarrow {\mathtt{x}} = -{\mathtt{2}}$$

but were did you get the 11 form

11 was in the equation!