please use lex $($using c compiler $)$ and yacc $($bison$)$ and then an implementation. send full solution please, thank you

Write a suitable Context$-$Free Grammar $($CFG$)$ to

parse the following equation. Implement the

grammar with any of your preferred programming

languages.

$y=1+\frac{nx}{1!}+\frac{n(n-1)x^2}{2!}+\frac{n(n-2)x^3}{3!}+\frac{n(n-3)x^4}{4!}$