### Theory:

Let us recall some of the basic concepts of polynomials.
Degree of the polynomial
If $$p(x)$$ is a polynomial in $$x$$, the highest power of $$x$$ in $$p(x)$$ is called the degree of the polynomial $$p(x)$$.
Example:
$$p(x)$$ $$=$$ $$5x^3 + 2$$

The highest power of the polynomial $$p(x)$$ is $$3$$.

Therefore, the degree of $$p(x)$$ is $$3$$.
Linear polynomial
A polynomial of degree $$1$$ is called a linear polynomial.
Example:
$$p(x)$$ $$=$$ $$2x + 3$$
A polynomial of degree $$2$$ is called a quadratic polynomial.
Example:
$$p(x)$$ $$=$$ $$2x^2 + x + 3$$
Cubic polynomial
A polynomial of degree $$3$$ is called a cubic polynomial.
Example:
$$p(x)$$ $$=$$ $$2x^3 + 3x^2 - 6x + 3$$
Value of the polynomial
If $$p(x)$$ is a polynomial in $$x$$, then for any real number $$k$$ the value obtained by replacing $$x$$ by $$k$$ in $$p(x)$$ is the value of the polynomial $$p(x)$$ at $$x=k$$.

The value of the polynomial $$p(x)$$ at $$x=k$$ is denoted by $$p(k)$$.
Zero of the polynomial
If the value of the polynomial $$p(x)$$ at $$x = k$$ is zero $$(p(k) = 0)$$, then the real number $$k$$ is called the zero of the polynomial $$p(x)$$.
Zero of a linear polynomial
If $$k$$ is the zero of the linear polynomial $$p(x)$$ $$=$$ $$ax +b$$, then $$p(k)$$ $$=$$ $$0$$.

This implies $$ak +b$$ $$=$$ $$0$$

So, $$k$$ $$=$$ $$\frac{-b}{a}$$.

In general, the zero of the linear polynomial $$p(x)$$ $$=$$ $$ax +b$$ is given by $$\frac{-b}{a}$$ $$=$$ $$\frac{-\left(\text{Constant term}\right)}{\text{Coefficient of }x}$$.