$${\frac{\left({\mathtt{4}}{\mathtt{\,\times\,}}{{\mathtt{yx}}}^{{\mathtt{3}}}\right)}{\left({\mathtt{4}}{\mathtt{\,\times\,}}{{\mathtt{yx}}}^{{\mathtt{4}}}\right)}}$$
The 4s cancel out, and the ys cancel out.
=x^3/x^4
The xs cancel out too much, leaving:
=x^-1
But since we can't use negative exponents, we can write it as:
=1/x
Instead.