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Let's say we want to determine what is the polynomial for $f(x)=(ax+b)^m$. We can get the derivatives of this:

$$ \begin{aligned} f^{(1)}(x) & = m \cdot a \cdot (ax+b)^{m-1}\\ f^{(2)}(x) & = (m-1) \cdot m \cdot a^2 \cdot (ax+b)^{m-2}\\ f^{(n)}(x) & = (m-n+1) \cdot (m -n+20 \cdot ... \cdot (m-1) \cdot m \cdot a^n \cdot (ax+b)^{m-n}\\ & = {{m!} \over {(m-n)!}} \cdot a^n \cdot (ax+b)^{m-n}\\ \end{aligned} $$
Getting the value of the derivatives now at zero:
$$ \begin{aligned} f(0) & = a^0 \cdot b^m \\ f^{(1)}(0) & = {{m!} \over (m-1)!} \cdot a^1 \cdot b^{m-1}\\ f^{(2)}(0) & = {{m!} \over (m-2)!} \cdot a^2 \cdot b^{m-2}\\ f^{(n)}(0) & = {{m!} \over (m-n)!} \cdot a^n \cdot b^{m-n}\\ \end{aligned} $$
Now we can deduce the Taylor Series:
$$ \begin{aligned} (ax+b)^m & = \sum_{j=0}^m {{m!} \over (m-j)!} \cdot a^j \cdot b^{m-j} \cdot {{x^j} \over {j!}}\\ & = \sum_{j=0}^m {{m!} \over (m-j)!j!} \cdot a^j \cdot b^{m-j} \cdot x^j\\ & = \sum_{j=0}^m {m \choose j} \cdot a^j \cdot x^j \cdot b^{m-j}\\ \end{aligned} $$