-4/9x=16/27

Divide 16/27 by -4/9 to isolate x.

$${\mathtt{9}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,\times\,}}{\mathtt{16}} = {\mathtt{\,-\,}}\left({\mathtt{4}}{\mathtt{\,\times\,}}{\mathtt{27}}\right)$$

$${\mathtt{x}} = {\mathtt{\,-\,}}{\frac{{\mathtt{108}}}{\left({\mathtt{9}}{\mathtt{\,\times\,}}{\mathtt{16}}\right)}}$$

$${\mathtt{x}} = {\frac{{\mathtt{3}}}{{\mathtt{4}}}} = -{\mathtt{0.75}}$$