Find f(x)\displaystyle {f{{\left({x}\right)}}} if y=f(x)\displaystyle {y}={f{{\left({x}\right)}}} satisfies
dydx=54yx17\displaystyle {\frac{{{\left.{d}{y}\right.}}}{{{\left.{d}{x}\right.}}}}={54}{y}{x}^{{{17}}} and the y\displaystyle {y}-intercept of the curve y=f(x)\displaystyle {y}={f{{\left({x}\right)}}} is 4\displaystyle {4}.

f(x)=\displaystyle {f{{\left({x}\right)}}}=   .