Use the binomial theorem to expand the following. $(6 x+7)^{4}

Step 1 ：First, we need to understand the binomial theorem. The binomial theorem states that for any positive integer $n$, the expansion of $(a+b{)}^n$ is given by $(a+b{)}^n=a^n+(\genfrac{}{}{0ex}{}{n}{1})a^{n-1}b+(\genfrac{}{}{0ex}{}{n}{2})a^{n-2}{b}^2+\dots +b^n$.

Step 2 ：In this problem, $a=6x$ and $b=7$, and $n=4$.

Step 3 ：We can substitute these values into the binomial theorem to get the expansion of $(6x+7{)}^4$.

Step 4 ：The first term is $(6x{)}^4=1296x^4$.

Step 5 ：The second term is $(\genfrac{}{}{0ex}{}{4}{1})(6x{)}^3\ast 7=4\ast 1296x^3\ast 7=36288x^3$.

Step 6 ：The third term is $(\genfrac{}{}{0ex}{}{4}{2})(6x{)}^2\ast 7^2=6\ast 1296x^2\ast 49=380160x^2$.

Step 7 ：The fourth term is $(\genfrac{}{}{0ex}{}{4}{3})(6x)\ast 7^3=4\ast 6x\ast 343=8232x$.

Step 8 ：The fifth term is $7^4=2401$.

Step 9 ：Adding all these terms together, we get the expansion of $(6x+7{)}^4=1296x^4+36288x^3+380160x^2+8232x+2401$.

Step 10 ：This is the simplest form of the expansion, so we have finished the problem.

Step 11 ：Finally, we check our result. The degree of the polynomial is 4, which is the same as the exponent in the original expression, so our result meets the requirements of the problem.