Step 1: First we have to write polynomials in descending order.

$$ \begin{aligned} P(x) &= 2b+4 \\ Q(x) &= 11b-4 \\ \end{aligned} $$

In this example we are multiplying two binomials so FOIL method can be used.

$$ \begin{aligned} \left( \color{blue}{ 2b+4}\right) \cdot \left( \color{orangered}{ 11b-4}\right) &= \underbrace{ \color{blue}{2b} \cdot \color{orangered}{11b} }_{\text{FIRST}} + \underbrace{ \color{blue}{2b} \cdot \left( \color{orangered}{-4} \right) }_{\text{OUTER}} + \underbrace{ \color{blue}{4} \cdot \color{orangered}{11b} }_{\text{INNER}} + \underbrace{ \color{blue}{4} \cdot \left( \color{orangered}{-4} \right) }_{\text{LAST}} = \\ &= 22b^2 + \left( -8b\right) + 44b + \left( -16\right) = \\ &= 22b^2 + \left( -8b\right) + 44b + \left( -16\right) = \\ &= 22b^2+36b-16; \end{aligned} $$

Polynomial Operations Calculator