Let's divide the polynomial by $x+7$ using synthetic division (also known as Ruffini's rule). First, write all the coefficients of the polynomial in the numerator in descending order based on grade (putting a zero if a term doesn't exist). Then, take the first coefficient ($1$) and multiply it by the root of the denominator ($-7$). Add the result to the second coefficient and multiply this by $-7$ and so on

In the last row appear the new coefficients of the polynomial. Use these coefficients to rewrite the new polynomial with a lower grade, and the remainder ($4$) divided by the divisor

Any expression multiplied by $0$ is equal to $0$